A Report on

The 64th
International
Mathematical
Olympiad
July 2nd - July 13th

国際数学オリンピック委員会

International Mathematical Olympiad Board
公益財団法人 数学オリンピック財団
Mathematical Olympiad Foundation of Japan

Contents 目 次
Preface 序文 
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1
Ⅰ IMO2023 Chiba, JAPAN Organization 組織 
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⚑ Organizing Committee 組織委員会⚒ Executive Committee 実行委員会⚓ IMO BOARD（IMOB） IMO 役員
Ⅱ Participants 参加者 
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⚑ Participants Summary Table 総括表（参加者役割別人数）⚒ Participanting Countries 参加国リスト•Leader 団長•Deputy Leader 副団長•Obsever A/B/C オブサーバー A/B/C⚓ Coordinators コーディネーター
⚔ Senior Coordinators シニアコーディネーター
Ⅲ Programme 大会プログラム 
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⚑ Leader・Obsever A・IMO Board 団長・オブザーバー A・IMO 役員⚒ Deputy Leader・Obsever B 副団長・オブサーバー B⚓ Contestant・Obsever C 選手・オブサーバー C
Ⅳ Ceremonies and Events 式典とイベント 
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⚑ Opening Ceremony 開会式⚒ International Cultural Exchange 国際文化交流•Excursion•steAm Culture Festival•Jane Street Hub•Sponsors Booths•Farewell Party⚓ Closing Ceremony 閉会式

Ⅴ Problems & Solutions 問題・解答
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⚑ Problems 問題
Ⅵ Results ＆ Awards 結果 
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⚑ Summary まとめ⚒ Statistics 統計⚓ Awarded Contestants 表彰選手
Ⅶ Information & Annual Regulations 通知と規則 
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⚑ Information for Contestants 選手への通知⚒ Regulations of the 64th International Mathematical Olympiad 第 64 回 IMO 規則
Ⅷ Goods グッズ
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41
⚑ Introduction of Goods & Medals グッズ・メダル紹介
Ⅸ Summary of Operations まとめ 
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43
⚑ Operation and Management⚒ Ceremony⚓ Contest⚔ Events⚕ Comments（After the IMO2023 Chiba, JAPAN）⚖ Balance Sheet 大会収支（バランスシート）
Ⅹ Photo Gallery ギャラリー 
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50
Ⅺ Sponsors スポンサー
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58

Preface
The 64th International Mathematical Olympiad in Japan” was held from July 2 (Sunday) to July 13(Thursday), 2023, mainly in Makuhari, Chiba City. This was the second time for Japan to host theGames, the first time in 20 years since the 44th Tokyo Games. The total number of participating
countries and regions was 112, with 618 athletes (including 67 women) and approximately 1,000
officials and executives from each country, making it the largest event of its kind ever held in Japan.
With the worldwide outbreak of coronavirus infection under control, there is a sense that the faceto-face world championships have recovered in earnest, and the number of participating countries
and regions is steadily expanding, and it is encouraging to see the interest and challenge inmathematics of the younger generation who will lead the future of society.
Looking back, the Executive Committee was formed in 2017, and in 2018, the general framework
was decided upon, with the contest venue to be Makuhari Messe and the main lodging location forcompetitors and others to be the APA Hotel & Resort. I would like to take this opportunity to thankall those involved both inside and outside the country who have been involved in the implementationof this competition as well as in its preparation over a long period of time, and JST and all sponsoring
companies, organizations, and individuals for their financial support.
At the conference, we were honored to receive congratulatory speeches from Keiko Nagaoka,
Minister of Education, Culture, Sports, Science and Technology, at the opening ceremony, andfrom Shunichi Kamiya, Mayor of Chiba City, at the closing ceremony. The opening ceremony
featured performances by taiko drummers and Tokyo Brass Style, and the closing ceremony wasfollowed by a welcome party with a band led by Sachiko Nakajima, a former Math Olympian, who
added her own special touch to the event. I am sure that both athletes and officials had a lot of fun
and that the event was a pleasant memory for all. On the other hand, the management of thetournament was not a simple task. Just prior to the event, there were times when delays in
preparations became apparent, and we were very concerned. However, the success of the event wasmade possible by the cooperation and understanding of the roles of the Executive Committee,
management staff, volunteers, and others, who were able to respond flexibly to various situations.
In fact, we have received many comments and opinions from the participants from various countries
praising the event.
This booklet summarizes the main points of the conference as a record of the conference resultsthat can be used for future reference. The following is a general report on the convention, includingorganization, participation, program, contest questions, contest results, excursions, and sponsors.
In particular, the results of the contests are expected to confirm that the level of the contests has
been increasing year by year in proportion to the scale of the contests. We also hope that the numberof people in each role and the size of the budget for running the convention will be helpful in
preparing for future conventions.
International conventions are often affected by national and global circumstances, and somecountries were unable to participate this year. I strongly hope that many countries will be able toparticipate successfully in the future conventions and that the international conventions will further
flourish. I am proud of the role that the Japanese convention played as a guidepost for thedevelopment of the international convention, linking the past to the future, but in the end, based on
the record of this convention in this booklet and on the IMO website, I await the evaluation of allconcerned and society at large. We would appreciate your frank evaluation and opinions.
Lastly, I would like to thank Mr. Yujiro Ito, Chairman of Sumitomo Mitsui Banking Corporation, aclassmate of mine from my junior and senior high school days, for his great help in arranging
accommodations and other matters. I would like to take this opportunity to thank him.
I would like to thank you all for your continued support and understanding of the Mathematical
Olympiad, and in return, I would like to express my gratitude to you all for your support of the Japan
Games.
March 2024
Mathematical Olympiad Foundation
Takahiko Fujita, President
1

Ⅰ IMO2023 Chiba, JAPAN 組織⚑

Organizing Committee

組織委員会

名誉会長
文部科学大臣委員長
ジブラルタ生命保険株式会社 代表取締役社長
副委員長
東京理科大学 栄誉教授
中央大学 教授（IMO2023 日本大会実行委員会委員長）
富士通株式会社 代表取締役社長
日本電信電話株式会社 相談役
株式会社公文教育研究会 代表取締役社長
株式会社ナガセ 代表取締役社長
株式会社東京出版 代表取締役社長
Arithmer 株式会社 代表取締役社長
一般社団法人 日本数学会 理事長
公益社団法人 日本数学教育学会 会長
委員
上野製薬株式会社 代表取締役社長
公益財団法人 豊田理化学研究所 所長
ヤフー株式会社 代表取締役社長 CEO
日本電気株式会社 執行役社長
明治安田生命保険相互会社 代表執行役社長
株式会社みずほフィナンシャルグループ 代表執行役社長
日本 IBM 株式会社 代表取締役社長執行役員
第一生命ホールディングス株式会社 取締役会長
日本生命保険相互会社 代表取締役社長
伊藤忠テクノソリューションズ株式会社 代表取締役社長
株式会社三菱 UFJ フィナンシャルグループ 代表執行役社長
株式会社三井住友フィナンシャルグループ 執行役社長
ロート製薬株式会社 代表取締役社長
公益財団法人 孫正義育英財団 ソフトバンクグループ代表
株式会社日立製作所 代表執行役社長 CEO
東亜薬品株式会社 代表取締役社長
カラクリ株式会社 代表取締役 CEO
三菱電機株式会社 代表執行役社長
東京海上日動火災保険株式会社 代表取締役社長
公益社団法人 日本アクチュアリー会 理事長
河合塾本郷校 K 会 チーフ
公益財団法人 日本数学検定協会 理事長
2

永岡 桂子
添田 毅司
秋山
仁
藤田 岳彦
時田 隆仁
篠原 弘道
池上 秀徳
永瀬 昭幸
黒木憲太郎
大田 佳宏
清水 扇丈
清水 美憲
上野 昌也
玉尾 晧平
小澤 隆生
森田 隆之
永島 英器
木原 正裕
山口 明夫
渡邉光一郎
清水
博
柘植 一郎
亀澤 宏規
太田
純
杉本 雅史
孫
正義
小島 啓二
中井
淳
小田 志門
漆間
啓
広瀬 伸一
上田 泰史
石井
潤
髙田
忍
2

⚒

Executive Committee

実行委員会

Member
委員長（数学オリンピック財団理事長） 藤田 岳彦
副委員長

前田 吉昭

委員

秋山
仁 ・ 淺井
石井志保子 ・ 小島
佐古 和恵 ・ 高木谷聖一 ・ 谷山新國
亮 ・ 福永森田 康夫 ・ 横田

オブザーバー（担当旅行会社：株式会社日本旅行）

藤間 貴子 ・ 江草 春奈 ・ 寺田江梨奈
新井 早紀 ・ 鳥生 慎祐 ・ 保科均

康明 ・ 安藤 哲哉
定吉 ・ 近藤 宏樹
悟 ・ 田﨑 慶子
公規 ・ 中島さち子
薫 ・ 宮下 三奈
佳之 ・ 若月宏

Finance manager 財務担当
淺井 康明 ・ 田﨑 慶子 ・ 宮下 三奈
Fund Raising manager 寄付金募集担当
前田 吉昭 ・ 淺井 康明
Problem Selection Committee（PSC）manager 問題選択委員会担当
安藤 哲哉
Coordination/Coordinator manager コーディネーション/コーディネータ担当
安藤 哲哉
Information Technology manager IT 担当
谷山 公規 ・ 谷聖一

Public Relations manager 広報担当
石井志保子
Schedule manager 進行計画担当
小島 定吉 ・ 前田 吉昭
Opening and Closing Ceremony manager 開会/閉会式担当
福永薫

Contest/Invigilate manager 試験実施/試験監督担当
近藤 宏樹 ・ 横田 佳之
Guides/Volunteers manager ガイド/ボランティア担当
前田 吉昭 ・ 谷山 公規 ・ 淺井 康明
Medals/Goods manager メダル/グッズ担当
佐古 和恵
Event/Excursion manager イベント/エクスカーション担当
前田 吉昭 ・ 中島さち子
Transfer manager 送迎担当
高木

悟 ・ 新國亮 ・ 横田 佳之

仁 ・ 若月宏

Advisor and Help manager アドバイザー担当
秋山International Jury Meeting manager 国際ジュリーミーティング担当
藤田 岳彦 ・ 安藤 哲哉
3

3

⚓

IMO BOARD（IMOB)IMO 役員Commissioner（コミッショナー）
Anastasiya Sudakova
Advisory Board（アドバイザリーボード）
Gregor Dolinar（President）・ Géza Kós
Dávid Kunszenti-Kovács
・ Ben Kirk
森田 康夫
・ Joseph Myers
System Director（システムディレクター）
Mctjaz Zeljko

44

1 Participants summary table

総括表（参加者役割別⼈数）

Ⅱ index
Participants
参加者
C(F)=contestant(Female),
L=Leader, DL=Deputy Leader

OA=Observer A, OB=Observer B, OC=Observer C, PSC=Problem Selection Committee

⚑
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

5

Coo=Coordinator, Gst=Guest, Vip=Very important person, Org=Executive organization,

Inv=Invigilator, Prs=Press, Sco=Senior Coordinator, Stf=Staff, Vol=Volunteer
ParticipantsGui=Guide,
Summary
Table 総括表（参加者役割別人数）
Cvol=Chiba Convention Bureau volunteer, Com=Commissioner

Country

C(F)

L

DL

ALB
ALG
ARG
ARM
AUS
AUT
AZE
BEL
BFA
BGD
BGR
BIH
BLR
BOL
BRA
BWA
CAN
CHI
CHN
CMR
COL
CRI
CUB
CYP
CZE
DEN
DOM
ECU
ESP
EST
FIN
FRA
GEO
GER
GHA
GTM
HEL
HKG
HND

6(1)
6
6
6
6(2)
6
6(1)
6(1)
6(2)
6
6(1)
6
6
6(1)
6
6(2)
6
3
6
6
6(1)
6
2(1)
6
6(1)
6(2)
6(2)
6
6
6
6(2)
6
6(1)
6
2
2(2)
6
6
2

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

1
1
1

OA

OB

2
1
2
2

2

1

1

OC

PSC

1

1

Coo

Gst

Org

1

1

1

1

3
1
1
1

Vip

1
1
1

1

2

1

1

1

1
1

1

1

1
2

4

1
1
1

5

Gui

Inv

Prs

Sco

Stf

Vol Chvol Com

40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86

Country

C(F)

L

DL

HRV
HUN
IDN
IND
IRL
IRN
IRQ
ISL
ISR
ITA
JPN
KAZ
KEN
KGZ
KOR
KSV
LIE
LKA
LTU
LUX
LVA
MAC
MAR
MAS
MDA
MEX
MKD
MMR
MNE
MNG
MRT
NIC
NLD
NOR
NPL
NZL
OMN
PAK
PAN
PAR
PER
PHI
POL
POR
PRI
ROU
RWA

6(2)
6(1)
6(1)
6
6(1)
6
4(1)
6
6
6
6
6
6
6
6
6
2
6
6
3(3)
6(1)
6
6(1)
6(1)
6
6
6
6(1)
4(1)
6
6
3
6
6(1)
6(1)
6(1)
6(3)
6
3
4(1)
6
6
6
6
4(2)
6
6(2)

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

OA

1
1

1
1

1

1

1
1
2
1

1

1

2

3
1

1
1

1

1

1
1

1
1
1
1
1
1
1
1
1
1
1
1
1
1

OB

OC

PSC

Coo

Gst

Org

Gui

Inv

Prs

Sco

Stf

Vol Chvol Com

23 117 40

25

6

49

14

1

1

2

9
1
2
2
1

65 104
1

1

47

1

1

2

2

4

1

1

2
1

2
1
1
1

1

1

1

3

2

Vip

1
6

6

87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112

Country

C(F)

L

DL

SAF
SAU
SGP
SLV
SRB
SUI
SVK
SVN
SWE
SYR
THA
TJK
TKM
TUN
TUR
TWN
TZA
UAE
UGA
UKR
UNK
URY
USA
UZB
VEN
VNM

6(1)
6
6
3(1)
6
6(1)
6(1)
6(2)
6(1)
6
6
6(1)
6
6
6(1)
6
1
6(3)
6(1)
6(4)
6
3
6
6
3(2)
6

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

計

1
1
1
1

618(67) 111 108

OA

OB

2
1

1
3
3

OC

Org

Gui

Inv

Prs

Sco

Stf

Vol Chvol Com

1
1

1

2

3
8

1
1
1
1
1

48

1
2

1

2

1

4
2
9

40

総計
902 summary table
1 Participants
1 Participants summary table

index
index

Vip

2

2

60

Gst

1

3
2

1

Coo

1

1

1
2

PSC

16

1

65 1241

25 117 40

26

8

51

14

総括表（参加者役割別⼈数）

471

総括表（参加者役割別⼈数）

C(F)=contestant(Female),
L=Leader,DL=Deputy
LeaderC(F)=contestant(Female), L=Leader,
DL=Deputy
LeaderOA=ObserverA,
A,OB=Observer
OB=Observer B,B,
OC=Observer
C, PSC=Problem
Selection
Committee
OA=Observer
OC=Observer
C, PSC=Problem
Selection
Committee

Coo=Coordinator, Gst=Guest,
Gst=Guest, Vip=Very
importantperson,
Org=Executive
organization,
Coo=Coordinator,
Vip=Very
importantperson,
Org=Executive
organization,
Gui=Guide, Inv=Invigilator, Prs=Press, Sco=Senior Coordinator, Stf=Staff, Vol=Volunteer

Gui=Guide, Inv=Invigilator, Prs=Press, Sco=Senior Coordinator, Stf=Staff, Vol=Volunteer
Cvol=Chiba Convention Bureau volunteer, Com=Commissioner

Cvol=Chiba Convention Bureau volunteer, Com=Commissioner
Country

1
2
3
4
5
6
7
8
9
10
11
12

C(F)

Country
1 ALBC(F) 6(1) L

ALB
2 ALG6(1) 6 1
3 ARG 6
6 1
ALG
4 ARM
ARG
6 6 1
5 AUS
6(2)
ARM
6
1
6 AUT
6
AUS
6(2)
1
7 AZE
6(1)
AUT
8 BEL 6 6(1) 1
AZE
9 BFA6(1)6(2) 1
10 BGDBEL
6(1) 6 1
11 BGR
BFA
6(2)6(1) 1
12
BIH
6
BGD
713 BLR 6 6 1
BGR
6(1)6(1) 1
14 BOLBIH
15 BRA 6
6 1

L

DL

OA

1 DL 1 OA

1 1 1
1 1 1
1 1 1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1 1 1
1 1 1
1
1
1
1
1
1 1
1
1 1 1

2
21
12
2

2
2

1

1

1

OB

OC

PSC

OB

OC

PSC

1

1

1

1

1

1

3

Gst

Coo

Vip

Gst

2

2

1

1

1

1

1

Coo

1
7

1
1

Org

Vip

Gui

Inv

Prs

Org

Gui

Inv

Sco

Prs

Stf

Vol Chvol Com

Sco

Stf

Vol Chvol Com

⚒Country

Participanting Countries
Leader

Deputy Leader

1

ALB

Adrian Naço

Enkel Hysnelaj

2

ALG

Abdallah Rahmani

Hacene Belbachir

3

ARG

Patricia Fauring

Martín Mereb

4

ARM

Smbat Gogyan

Gurgen Asatryan

5

AUS

Angelo Di Pasquale

Hadyn Tang

6

AUT

7
8
9
10
11
12
13

AZE

Robert Geretschläger

Mammadov Abbas

参加国リストVeronika Schreitter

Hasan Hasanzade

BEL

Bart Windels

BGD

Mahbubul Alam Majumdar Nur Muhammad Shafiullah

BFA

BGR
BIH

BLR

Philippe Niederkorn

Innocent Bayala

Cye Antonio Angelberg Kambire

Stanislav Harizanov

Stoyan Boev

Adisa Bolić

Goran Janković

David Zmiaikou

ObserverA
Abdeldjalil Hezouat

ObserverB

ObserverC

Maya Chouikrat

Younes El Maamoun Benyahia Abdelhamid Benmezai

Daniel Perrucci

Tigran Margaryan

Bojan Bašić

Adrian Agisilaou
Ben Kirk

Ria Van Huffel

Michelle ChenLouise Bilston

Guliyev Vugar

Md. Baizid Bhuiyan

Stefan Gerdjikov

Dzmitry Bazyleu

14

BOL

Cordero Cárdenas Sonia Ximena Nivia

Pozo Vargas Joel Ruben

15

BRA

Edmilson Motta

Samuel Barbosa Feitosa Fabio Dias Moreira

16

BWA

Mmoloki Lekhutlile

Mathews Masole

CHI

Anibal Velozo

Davi Lopes Alves de Medeiros

17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32

CAN

CHN

CMR
COL
CRI

CUB
CYP
CZE

Antonio Molina Lovett

Liang Xiao

Caleb Ji

Howard Halim

Zhenhua Qu

Yunhao Fu

Anibal Velozo

Joseph Marie Domguia

Adrien Herve Benyomo Etoga

Daniel Campos Salas

Oscar Zamora Luna

Maria E Losada

Demetres Christofides

Tomáš Bárta

Stelios Kouzaris
Pavel Calábek

ECU

Jorge Chamaidan

Susanna Belussi

Jhosue Infante

ESP

Adel Darwish

FIN

Ville Uotila

Daniel Arone

FRA

Oleg Košik

Vincent Jugé

Zyad Hassan
Hendrik Vija

Théo Lenoir

GEO
GER

George Chelidze

Givi Nadibaidze

34
35

GHA

Yuka Machino

Joel Dogoe

36

GTM

José Carlos Bonilla Aldana

HKG

Tak Wing Ching

33

37
38
39

HEL

Uwe LeckAnargyros Fellouris

Eric Müller

Silouanos Brazitikos

Long Tin Chan

Chris Peterson

Ka Lok Chan

Sahil Mhaskar

Fajar Yuliawan

Farras Mohammad Hibban Faddila

Prithwijit De

Anant Mudgal

Pranjal Srivastava

Amin Behjati

Navid Safaei

Ali Partofard

IRLMark Flanagan

45

IRN

Seyed Hessam Firouzi

46

IRQ

Abdullah Muqdad Mawlood Alani Ekram Rahim Ghaffar Ghaffar

IND

ISL

Marteinn Hardarson

Emmanuel Barima Manu
Theodora Tsiachta

Ka Ho Law

Sándor Dobos

44

47

Jeannette Lacoss

Viktor Harangi

Aleams Barra

43

Giorgi Svanadze

HUN
IDN

42

Jens Reinhold

Devis Moisés Alvarado Zavala Luis Armando Ramos Palacios

Borna Vukorepa

41

Heikki Pokela

HND
HRV

40

Kewen Li

Evidio Quintana Fernández

Malthe David Søholm Mejlsted Marius Christian Fischer

EST

Bin WangSantiago RodríguezDEN

DOM Cesar Santil

Regis Prado Barbosa

Tapologo Mabotho

Vlatko Crnković
Nanang Susyanto

Luke GardinerMatin Yadollahi

Roohollah Oraki Kohshoor

Sigurður Jens Albertsson

88Country

Leader

Deputy Leader

ISR

Ilya Gringlaz

49

ITA

Dan Carmon

50

JPN

Sogo Murakami

Keiko Tasaki

51

KAZ

Assylbek Issakhov

Kanat Satylkhanov

48

Massimo Gobbino

Samuele Mongodi

52

KEN

Elijah Matoke Charles

James Kiwanuka Katende

53

KGZ

Bekzhan Dzhumabaev

Makhamadkhan Ishmatov

54
55
56
57
58
59
60
61
62
63
64

KOR
KSV

Suyoung Choi
Armend Shabani

LIE

Valentin Imbach

LTU

Artūras Dubickas

LKA

Dayal Dharmasena

Hwajong Yoo

MDA

Hassan Asensouyis

Mohamed El Ibbaoui

MEX

66

MKD Ilija Jovceski

Mirko Petrushevski

67

MMR Saw Win Maung

Htin Aung

MNE

Nikola Konatar

MNG Otgonbayar Uuye

70

MRT

Batbayasgalan Balkhuu

Mahfoudh Mohamed Ammou Ahmed Mohamed Yahya Mohamed Abdellahi Deyah

Oscar Danilo Quintanilla Luna

73

NOR

Dávid Kunszenti-Kovács Andreas Alberg

74

NPL

Sanat Kumar Acharya

Chhabi Dhungana

75

NZL

Ross Atkins

Josie Smith

76
77
78

NLD

Quintijn Puite

Johan Konter

OMN

Mian Mohammed Salim Al Hinai Amal Nasser Said Al Muqarshi

PAN

Luis Gabriel Peña García Luis Alberto Modes Castillo

PAK

Sarfraz Ahmad

PAR

Nair Isabel Aguilera Martínez Dario de Jesus Torres Herebia

PER

Jonathan Farfan

81

PHI

Hazel Joy Shi

Kerish Villegas

82

POL

Tomasz Cieśla
Luis Caceres

Nuno Miguel Arala Santos

84

PRI

Joana TelesŁukasz Bożyk

85

ROU

Cătălin Gherghe

Mihai Chis

86

RWA

Jean Nepo Munezero

83

POR

SAF

87

9

Yongjin Song
Ringi Kim

Gyeonghui Park

Hongnyung Kim
Kyeongsik Nam

Lirie Aliu

Nazgul Kuzekeeva

Chaerin Lee

Hyun Hui Lee

Miradije Berisha

Mahmoud Essamet

Mohammed Dahmouni

Muhammad Zafree Bin Zaharidan

Liam Baker

Nikica Davkova

Teodora Boshkova

Batzorig Undrakh
Bayarmagnai Gombodorj

Omar Colon

Khulan Tumenbayar

Bazar Tumurkhan

Dayantsolmon Dagva

Davaasuren Davaadorj
Baigali Jigjid

Isselmou Lebatt Farajou
Nils Van de Berg

Allie Zong

Bhadra Man TuladharHari Prapanna Kandel

Nirula Tamrakar
Kevin Shen

Narayan Paudel
Jamie Craik

Ali Nasser Hamdoon Nasser Al Rashdi

Hani Shaker

80

79

Mirdin Eshenaliev

Gojko Jelovac

NIC

72

Carey Odhiambo Odoyo

Kevin William Beuchot Castellanos José Ignacio Barradas Bribiesca Adán Medrano Martín del Campo

69

71

Nurbek Kungozhin

Valeriu Baltag

65

68

Arailym Suleimenova

Filips Jelisejevs

Sio Meng Lao

Syamil Bin Ahmad Shakir Nor Ainun Binti Mat

Valeriu GuțuNaoki Watanabe

Zina Šiaulienė

Ieng Tak LeongMAS

ObserverC

Chethana Chathuprabha Belpa Godage

MAC
MAR

ObserverB

Alon Heller

Atsuya Ishida

Valmir Krasniqi

Zeihen Pascal André Jules Dostert Mike

Kims Georgs Pavlovs

Alessandra Caraceni

Johann Williams

LUX
LVA

ObserverA

Omri Zemer

Jamal Nasir

Russelle Guadalupe
Josette Biyo

Randolf Sasota

Lucian Turea
Erzsebet Anna (Elisabeta Ana) Nagy (Naghi)

Honorine Munezero

Marthe Uwiringiyimana
Kerry Jean Porrill

Malwande Nqobani Nkonyane

9

Muhammad Ali

Leader

Deputy Leader

SAU

Sultan Albarakati

ALzubair Habibullah

89

SGP

Yong Sheng Soh

Lixing Zong

90

SLV

Christopher Edgardo Padilla Sandoval Fernando Daniel Domínguez Castaneda

SUIDavid Rusch

Country
88

91
92
93
94

SRB

Miljan Knežević

Teodor von Burg

SVK

Stanislav Krajči

Martin Vodička

SVN

Luka Horjak

Omran Kouba

Leen Qasem

THA

Nithi Rungtanapirom

Teeradej Kittipassorn

96

SYR

Victor Ufnarovski

97

David Wärn

TJK

TKM

Pirahmad Olimjoni

Akmaljon Kholiqov

99
100

TUN

Taoufik Charrada

Raouf Thabet

101

TUR

Azer Kerimov

Selim Bahadır

102

TWN

Yen-chi Roger Lin

Chu-Lan Kao

103

TZA

Bussury Abdulrahman Omary Mwinyishekhe Muhamadi Kibinda

105

UGA

Joseph Ssebuliba

Medi Ssesanga

106

UKR

Bogdan Rublov

Zarina Kodyrova

98

104

UAE

Arslan Hojiyev

Josef Tkadlec

Tarek Shehata

Tiong Seng Tay

Tanish Patil

Gregor Dolinar

SWE

95

ObserverA

Safwat Abdelsalam

ObserverB

Faisal ALquayti
Majed ALharbi

Shaden ALshammari
Wee Kean Tan
Xu Chen Tan

Yangyi, Aloysius Ng

Annalena Hofer

Ahmad Alkhamis
Sarita Bunsupha

Penying Rochanakul

Palvan Agamyradov

Supanat Kamtue

Jaray Panmuang

Alaeddine Sabbagh
Monia Daghmouri Bouzouita

Hatice Dağlıoğlu

Mahmut Kamil Koçin
Ahmet İleri

Ming Hsiao

Chun-Chen Yeh

Wan-Chi Lin

Chiun-Chang Lee

Fatma Mahmood Yousuf Ali Aljanahi

Oleksandr Dashkov
Ihor Pylaiev

Andrii Anikushyn

Karen Kebirungi

Emily ChowJohn Collins

Ava Yeo

Patrick Gaule

UNK

Dominic Yeo

Freddie Illingworth

Omar El HousniCharles Leytem

Aiden David Rujumba

Svitlana Mystiuk

Rebecca Elcome

107

ObserverC

James Tennet

Joseph Myers

Ander Lamaison
Geoff Smith

URY

Hernán Puschiasis

UZB

Po-Shen Loh

Utkir Boltaev

Carl Schildkraut

110
111

VEN

Rafael Sánchez

Francisco Javier Molina Tirado

108
109

USA

Umid RakhmonovLuke Robitaille

Oleksandr Rudenko

Khakimboy Egamberganov
Marissa Carolina Cordido Martínez

Simón Andrés Puyosa García

Duy Kha Nguyen
Cong Hong Sai

Trong Khanh Truong
112

VNM

Anh Vinh Le

Ngoc Diep Tran

Ba Khanh Trinh Le

Viet Anh Trinh

Tang Vu Nguyen

Ngoc Minh Hoang
Duc Thinh Le

Thanh Do Nguyen

10

10

⚓

Coordinators

コーディネーターÁkos

Záhorský

Tímea

CsahókIldar

Maratovich Gaisin

Yuji

Odaka

Horace Claudio

Chaix

Michael

Ren

Jeck

Lim

Larry

Lau

Donghyun

Kim

Dylan Shan Hong

Toh

Shanta Singh

Laishram

Rikimaru

KurataSatoshiHayakawa

Mihir

SinghalZhao Yu

Ma

Zack

Chroman

Lovro

Drofenik

RyotaroKosugeJaka

Vrhovnik

James

Lin

YusukeNakamura

Ryosuke

Odoi

Yuki

YoshidaMinkyuChoi

Fuma

Hirayama

Milan

HaimanYuka

WatabeTakuyaInoue

Hiromasa

Kondo

Shuho

Kanda

Naoki

KimuraSoji

KubotaTaiyo

KodamaYuwan

Seo

Kensuke

YoshidaKei

Irie

Taisuke

HoshinoJunghunJu

Youngjun

Cho

Seongbin

Jeon

Yoshiki

Oshima

Dain

Kim

Yui

HosakaKoichiro

Kobayashi

SohKumabeNaoki

KurodaStephan

Wagner

Vesna

Kadelburg

Stijn

Cambie

Yuhi

Kamio

Yuan

Yao

YuliyaKryvitskayaJeonghyun

Ahn

Anna

Luchnikov

Jimin

Kim

Heizo

Sakamoto

DaejunLee

Kota

Tokoro

Shogo

Murai

Tomoki

YoshidaMasaki

Nishimoto

Elena-Madalina

Persu

Ayato

Shukuta

Alec

Sun

Ahmed Ittihad

Hasib⚔ Senior Coordinators

シニアコーディネーター

Shingo

Saito

Ander

LemaisonOmar

El Housni

Geoff

Smith

JosephMyers

Sung Jin

Park

Charles

LeytemNouzhaEl Yacoubi

1111

Ⅲ Programme 大会プログラム⚑

Leader・Obsever A・IMO Board
Date

July 2 Sunday

July 3 Monday

July 4 Tuesday

July 5 Wednesday

July 6 Thursday

Jury 7 Friday

July 8 Saturday

団長・オブザーバー A・IMO 役員

Time Table

Remarks

18：00‒20：00

Dinner

Early Arrival

9：00‒18：00

Arrival at Narita or Haneda airport

成田空港/羽田空港
ホテル日航成田

9：00‒12：00

IMOB Meeting

12：00‒14：00

Lunch

14：00‒18：00

IMOB Meeting

18：00‒20：00

Dinner

20：00‒22：00

Jury Meeting

7：00‒ 9：00

Breakfast

9：00‒11：30

Jury Meeting or Work on Short List

11：30‒13：30

Lunch

13：30‒18：00

Jury Meeting or Work on Short List

18：00‒20：00

Dinner

20：00‒22：00

Jury Meeting

7：00‒ 9：00

Breakfast

ホテル日航成田

ホテル日航成田

9：00‒11：30

Jury Meeting

11：30‒13：30

Lunch

13：30‒18：00

Jury Meeting

18：00‒20：00

Dinner

20：00‒22：00

Jury Meeting

7：00‒ 9：00

Breakfast

9：00‒11：30

Jury Meeting

11：30‒13：30

Lunch

13：30‒18：00

Translation

18：00‒20：00

Dinner

20：00‒22：00

Jury Meeting

7：00‒ 9：00

Breakfast

9：00‒11：30

Jury Meeting

11：30‒13：30

Lunch

13：30

Buses depart to Makuhari Messe

14：00‒14：30

Enter in Ceremony Hall

15：00‒16：40

Opening Ceremony

幕張メッセ国際会議場

17：00

Buses depart to Hotel Nikko Narita

コンベンションホール AB

18：00‒21：00

Party

ホテル日航成田

21：00‒22：00

Jury Meeting

7：00‒ 9：00

Breakfast

ホテル日航成田

ホテル日航成田

ホテル日航成田

9：00‒10：00

Q&A

10：00‒11：00

Jury Meeting

11：00‒13：00

Lunch

13：00‒18：00

Excursion

成田コース/佐原コース

18：00‒20：00

Dinner

ホテル日航成田

12

12

Date
July 9 Sunday

Jury 10 Monday

Jury 11 Tuesday

July 12 Wednesday

Time Table
7：00‒ 9：00

Breakfast

Remarks
ホテル日航成田

9：00

Check out Hotel Nikko Narita

9：00‒10：00

Q&A

10：00‒11：30

Jury Meeting

11：30‒13：30

Lunch

13：30

Buses depart to Makuhari APA hotel

15：00

Check in Makuhari APA hotel

15：00‒18：30

Free time

18：30‒20：30

Dinner東京ベイ幕張ホール

アパホテル＆リゾート

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

9：00‒12：00

Coordination

幕張メッセ Event Hall

12：00‒14：00

Lunch

東京ベイ幕張ホール

14：00‒18：00

Coordination

幕張メッセ Event Hall

18：00‒20：00

Dinner東京ベイ幕張ホール

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

9：00‒12：00

Coordination

幕張メッセ Event Hall

12：00‒14：00

Lunch

東京ベイ幕張ホール

14：00‒18：00

Coordination

幕張メッセ Event Hall

18：00‒20：00

Dinner東京ベイ幕張ホール

20：00‒20：30

Move to Hotel Springs

20：30‒22：00

Final Jury Meeting

Hotel Springs

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

9：00‒10：30

Final Jury Meeting

Hotel Springs

12：00‒14：00

Lunch

東京ベイ幕張ホール

14：00‒14：30

Move to Makuhari Messe

15：00‒17：30

Closing Ceremony

幕張メッセ国際会議場
コンベンションホール AB

Jury 13 Thursday

13

18：00‒20：00

Farewell Party

東京ベイ幕張ホール

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

10：00

Check out Makuhari APA hotel

アパホテル＆リゾート

10：00～

Departure

成田空港 / 羽田空港

13⚒

Deputy Leader・Obsever B
Date

July 6 Thursday

Jury 7 Friday

副団長・オブサーバー B

Time Table

Remarks

15：00

Check in Makuhari APA hotel

15：00‒18：00

Free time

18：00‒20：00

Dinner東京ベイ幕張ホール
東京ベイ幕張ホール

7：00‒ 9：00

Breakfast

9：00‒11：00

Free time

11：00‒13：00

Lunch

13：00‒14：00

Move to Makuhari Messe

15：00‒17：00

Opening Ceremony

アパホテル＆リゾート

幕張メッセ国際会議場
コンベンションホール AB

July 8 Saturday

July 9 Sunday

Jury 10 Monday

Jury 11 Tuesday

July 12 Wednesday

17：00‒18：00

Free time

18：00‒20：00

Dinner東京ベイ幕張ホール

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

9：00‒13：00

Free time

13：00‒14：00

Lunch

14：00‒18：30

Free time

18：30‒20：30

Dinner

7：00‒ 9：00

Breakfast

9：00‒13：00

Free time

13：00‒14：00

Lunch

14：00‒18：30

Free time

18：30‒20：30

Dinner

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

9：00‒12：00

Coordination

幕張メッセ Event Hall

12：00‒14：00

Lunch

東京ベイ幕張ホール

14：00‒18：00

Coordination

幕張メッセ Event Hall

18：00‒20：00

Dinner東京ベイ幕張ホール

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

9：00‒12：00

Coordination

幕張メッセ Event Hall

12：00‒14：00

Lunch

東京ベイ幕張ホール

14：00‒18：00

Coordination

幕張メッセ Event Hall

18：00‒20：30

Dinner東京ベイ幕張ホール

20：30‒22：00

Final Jury Meeting

Hotel Springs

東京ベイ幕張ホール

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

9：00‒10：30

Final Jury Meeting

Hotel Springs

12：00‒14：00

Lunch

東京ベイ幕張ホール

14：00‒14：30

Move to Makuhari Messe

15：00‒17：30

Closing Ceremony

幕張メッセ国際会議場
コンベンションホール AB

Jury 13 Thursday

18：00‒20：00

Farewell Party

東京ベイ幕張ホール

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

10：00

Check out Makuhari APA hotel

アパホテル＆リゾート

10：00～

Departure

成田空港/羽田空港

14

14

⚓

Contestant・Obsever C
Date

July 6 Thursday

Jury 7 Friday

選手・オブサーバー C
Time Table

Remarks

15：00

Check in Makuhari APA hotel

15：00‒18：00

Free time

18：00‒20：00

Dinner東京ベイ幕張ホール
東京ベイ幕張ホール

7：00‒ 9：00

Breakfast

9：00‒11：00

Free time

11：00‒13：00

Lunch

13：00‒14：00

Move to Makuhari Messe

15：00‒17：00

Opening Ceremony

アパホテル＆リゾート

東京ベイ幕張ホール
幕張メッセ国際会議場
コンベンションホール AB

July 8 Saturday

17：00‒18：00

Free time

18：00‒20：00

Dinner東京ベイ幕張ホール
東京ベイ幕張ホール

6：00‒ 8：00

Breakfast

8：00‒ 8：30

Move to Makuhari Messe

9：00‒13：30

Exam 1

幕張メッセ国際会議場
コンベンションホール AB

July 9 Sunday

13：30‒16：00

Lunch

16：00‒18：00

Free time

東京ベイ幕張ホール

18：00‒20：00

Dinner東京ベイ幕張ホール

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

8：00‒ 8：30

Move to Makuhari Messe

9：00‒13：30

Exam 2幕張メッセ国際会議場
コンベンションホール AB

Jury 10 Monday

Jury 11 Tuesday

July 12 Wednesday

13：30‒16：00

Lunch

東京ベイ幕張ホール

16：00‒18：00

Free time

Optional tour

18：00‒20：00

Dinner東京ベイ幕張ホール

19：00‒20：30

Culture Festival free activity

7：00‒ 8：30

Breakfast

8：00‒ 9：30

Departure for Tokyo Disneyland

東京ベイ幕張ホール

9：00‒18：00

Excursion TDL

東京ディズニーランド

18：00‒20：00

Dinner東京ベイ幕張ホール

19：00‒21：30

Culture Festival free activity

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

9：30‒17：00

Excursion

Optional tour

18：00‒20：30

Dinner東京ベイ幕張ホール

19：00‒21：30

Culture Festival free activity

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

9：00‒11：30

Free time

11：30‒14：00

Lunch

14：00‒14：30

Move to Makuhari Messe

15：00‒17：00

Closing Ceremony

18：00‒20：00

Farewell Party

東京ベイ幕張ホール

7：00‒ 9：00

Breakfast

東京ベイ幕張ホール

10：00

Check out Makuhari APA hotel

アパホテル＆リゾート

10：00～

Departure

成田空港/羽田空港

東京ベイ幕張ホール
幕張メッセ国際会議場
コンベンションホール AB

Jury 13 Thursday

15

15

Ⅳ Ceremonies and Events
１

Opening Ceremony〇Date and Time：Friday,July7,2023〇Place：Makuhari Messe International Exhibiti on Hall Convention Hall AB〇Program
・Contestants & Leaders Admission/seating
・Opening Wadaiko（荒川社中）・Opening Remarks■Minister of Education,Culture,Sports,Science and Technology
Keiko Nagaoka（永岡桂子）■IMO Board President

Gregor Dolinar■Contestants representative osth

Japanese national team ContestantKeisuke Koide（小出慶介）■IMO2023 Organizing Committee Chairman
The Gibraltar Life Insurance Co.,Ltd.CEO・Attraction

Tsuyoshi Soeda（添田毅司）

Music performance Tokyo Brass Style（東京ブラスタイル）

・Participating Countries & Contestants Introduction
・Closing Remarks■IMO2023 Japan Executive Committee Chairman
The Mathematical Olympiad Foundation of Japan Chairman
Takahiko Fujita（藤田岳彦）
・Closing

Leaders & Contestants Exit

■Minister of Education,Culture,Sports,Science and Technology

Keiko Nagaoka

Good afternoon, everyone!
I am Nagaoka Keiko. Minister of Education,Culture,Sports,Science and Technology ofJapan. I am very happy to be saying a few words at this opening ceremony for the 64th
International Mathematical Olympiad. First, let me warmly welcome all of you who havecome from countries and regions around the world to Japan.
The International Mathematical Olympiad provides an opportunity for motivated andtalented students to compete against their peers, and thus greatly and contributes to their
growth.
Japan has long been supporting this competition, and it is a great pleasure for Japan to beable to historic International Mathematical Olympiad. Mathematics can be said to be thecommon language for various sciences. It is an invaluable academic field that elucidates
the fundamental principles of all phenomena prevalent in industry, the environment, andlife itself, and predicts the signs of changes.
Moreover, mathematics is tied to solving the many social problems we are facing, such as
using data science to make more accurate weather forecasts.
I believe that the society you will live in from now will hold great possibilities while16presenting various challenges. Within that context, in order to open up these new
possibilities and solve problems, it will be essential to have young people who have aflexible mindset, think for themselves, and have the motivation and capability to take onthese difficult problems while also cooperating with others.
All of you have the potential to take advantage of the experience you gain here at thisOlympiad to further develop science and technology and create new technologies.
I hope that you will use your gifts to help lead the world and create a better society inthe future. At this Olympiad, I expect that you will all fully demonstrate your abilities andthe fruits of your efforts up to now and tackle the problems given with your all-out efforts
so you leave here with no regrets. I also hope you to take on these difficult problems while
also cooperating with others.
Finally, I want to express my highest regards to all those who have made such efforts forthe holding of this Olympiad and my sincere wish that this wonderful competition willcontinue to develop in the future. And last but not least, I sincerely hope that all of you
young people aspiring to study mathematics will make even greater strides forward.
Thank you very much.

17

■The Gibraltar Life Insurance Co.,Ltd. CEO

Takeshi Soeda

I am pleased to welcome all the contestants and participants from around the world to the 64th
International Mathematical Olympiad in Japan. I am Soeda Takeshi from Gibraltar Life
Insurance and Chairman of IMO2023.
I am thrilled to hold the IMO in Japan again for the first time in 20 years since the last IMO
was held in Japan in 2003. From bottom of my heart, welcome to Japan. While most of Covid19related travel restrictions have now been lifted here in Japan, you must have overcome many
challenges to participate in this event.
I am proud that all the contestants who have single-heartedly challenged the possibilities ofmathematics amidst such difficulties are now able to demonstrate their abilities to the fullest inJapan and deepen exchanges with other contestants from around the world. We, at the IMO
Committee, will provide all necessary support to help contestants to participate in thecompetition in a perfect condition, so we hope that everyone gives their best. I also hope thatyou enjoy Japanese culture during your stay and go back to your country with full of funmemories.
Finally, I would like to express my sincere gratitude to the Executive Committee and everyone
who has rendered support to the hosting of IMO2023 in Japan. Let me conclude my speechwith best wishes for success in the competition and further development of the International
Mathematical Olympiad.

18

2International Cultural Exchange<Excursion>
The Tour for Leaders

Date and Time : Saturday, July 8, 2023, 13:00-16:00
Two options (Course A and Course B) are selected according to the leader’s preference.
(1) Course A “Naritasan Shinshoji Temple Tour

Departure from hotel (Hotel Nikko Narita)
Arrive at Naritasan Shinshoji Temple

Visit Shinsho-ji Temple (guided by avolunteer guide in the temple precincts)

Free time (stroll through the streets full of
Edo atmosphere)

Departure from Shinsho-ji Temple
Arrive at hotel(2) Course B “Sawara Townscape Tour

Naritasan Shinshoji Temple

 Depart from hotel (Hotel Nikko Narita) Arrival at Sawara Machinami

 Free time (walk along the historical townscape) Ino Tadataka Memorial Museum Sawara Mitsubishi Museum

 Nakamuraya Shop (Japanese goods)
 Boat tour Old houses

 Hibashi Bridge
 etc.

 Sasen Plant

 Arrival at hotel

Ino Tadataka Memorial Museum

The Tour for contestants Tokyo Disneyland

Date & Time: July 10, 2023 (Monday) 9:00-18:00
To: From the hotel (Makuhari APA Hotel) by private bus
Return: Each country (team) will return to their
lodgings
Free time for each country (team) in TDL(accompanied by team guide)

Tokyo Disneyland
19

Team Tour

Date and time: July 11, 2023 (Tuesday) 9:00-18:00
The tour will be divided into the following 10

courses, depending on the wishes of theparticipants.

(1) Tour of the University of Tokyo's Kashiwa
Campus + Akihabara/Kappabashi walk(2) Visit Meiji Yasuda Life Insurance Company +stroll through Asakusa and Sky Tree

(3) Visit to the Japan Agency for Marine-Earth

University of Tokyo's Kashiwa Campus

Science and Technology (JAMSTEC) Yokohama Institute for Marine-Earth Science andTechnology(3) Visit to JAMSTEC (Japan Agency for Marine-Earth Science and Technology) +Walking tour of Minato Mirai and Red Brick Warehouse

Visit to METoA Ginza (Mitsubishi Electric Event Square, Ginza)(4) Tour of METoA Ginza (Mitsubishi Electric Event Square, Ginza) + Stroll around Zojoji
Temple, Shiba Park, and Tokyo Tower(5) Visit to NTT Musashino R&D Center(6) Visit Karakuri Corporation (Tsukiji) Experience Hall

(7) Visit to the Tokyo University of Science Math Experience Center (MUSE) + Walking
tour of Asakusa, Kappabashi, and Tokyo Sky Tree

(8) Visit Meiji Jingu Shrine, Harajuku, and Shibuya(9) Walking tour of Ueno Park and Akihabara(10) Play sports (tennis, soccer) at Kanda University of International Studies(*) For (1) to (4) and (6) and (7), outbound: by private bus, return: by own transportation.
(5) is round trip by private bus. (8) to (10): round trip by bus, return by own transport＜Culture Festival>

From July 9 (Sun.) to July 11 (Tue.), 2023, from 18:00 to 21:00, a Japanese cultural experienceexchange (workshop) was held with the following menu. The venue was Tokyo Bay MakuhariHall (1st floor), and participants were free to attend.
Urasenke Tea Ceremony (July 9)

Furoshiki (wrapping and knotting)” (July 10 & 11)

Mosaic Puzzle Art - Math x Art Works” (July 9 & 11)
Origami - Math x Origami” (July 9-11)

Math and Music” (July 9-11: Introduction of music goods & July 12: Farewell Party)＜Jane Street Hub>The following menu was offered as part of the Jane Street Hub activities during the Makuhari
dates of July 6-11, 2023, from 9:00 to 21:30.
Alumni/Contestants'Meeting space

A free space was set up on the first floor of Tokyo Bay Makuhari Hall where IMO competition

alumni and competitors could freely mingle. Mathematical discussions, sharing of experience,exchanges through mathematical games (Othello, chess, card games, smartphone games, etc.),
and renewal of old friendships were actively conducted during the period.
20

＜Sponsors Booth>On Sunday, July 9 from 15:00 to 21:00 and Monday, July 10 to Tuesday, July, 11 from 9:00 to
12:00, sponsors set up booths on the 46th floor of APA Hotel & Resort Tokyo Bay Sky Banquet

and the 1st floor of Tokyo Bay Makuhari Hall to introduce their companies, and players had
the opportunity to hear from company representatives freely. The booths were set up by
IMOF sponsors.

The booths were set up by IMOF sponsors HUAWEI and QuantCo (APA Hotel & Resort

46th floor), IMO2023 sponsors Gibraltar Life Insurance, FUJITSU, Arithmer, and IBM (APA
Hotel & Resort 46th floor), KARAKURI, YAHOO! JAPAN” and ‘Jane Street Hub’ (1st floorof Tokyo Bay Makuhari Hall).

<Farewell Party>

On Wednesday, July 12, 2023 from 18:00 to 20:00, a “Farewell Party” was held on the 2nd
floor of Tokyo Bay Makuhari Hall after the closing ceremony. A standing buffet party withlive background music, a live band performance, and the Bon Odori dance “Prime Number
Dance” as an attraction brought the venue together and provided a grand finale.

３

Closing Ceremony〇Date and Time：Wednesday,July12,2023 15:00～17:40〇Place：Makuhari Messe International Exhibiti on Hall Convention Hall AB〇Program

・Contestants & Leaders admission/seating
・Opening Digest VTR Screening
・Opning Remarks■Mayor of Chiba City

Shunichi Kamiya（神谷俊一）■IMO2023 Japan Executive Committee Chairman

The Mathematical Olympiad Foundation of Japan Chairman

・AwardTakahiko Fujita（藤田岳彦）

・Honorable Mention

192

people90people・Bronze

170

・Gold

54

・Perfect Score

5・Silver・Ｍirzakhani Awards

・General review

peoplepeoplepeopleIMO Board President Gregor Dolinar

・IMO flag Inheritance Ceremony
・Next host country Introduction
・Closing Remarks

5

peopleVTR■IMO2023 Japan Executive Committee Chairman

The Mathematical Olympiad Foundation of Japan Chairman
Takahiko Fujita（藤田岳彦）

Closing Leaders & Contestants Exit21

■ Mayor of Chiba Kamiya Shunichi

My name is Kamiya Shunichi and I am the Mayor of Chiba City. On the behalf of the980,000 citizens of Chiba City, I am delighted to be able to welcome all of the participants
here today, who have made the long journey from all over the world. It is a huge honour
for Chiba City to host this year’s International Mathematical Olympiad.
Chiba City is known for its historical Kasori Shell Mounds and the Chiba Clan, as well as
nature, such as greenery, the coastline and the bay area. The city is also characterized byits urban facilities, where people are able to enjoy the convenience and ease of being able
to work close to their homes.
Many people come to Chiba City from Tokyo and abroad to work, study and shop, as
Chiba City is quite accessible due to its excellent transport network.
Furthermore, Chiba City has a long-running connection with science and technology, as
the founding father of rocket research in Japan, Dr.Hideo Itokawa, first began his spaceresearch here in Chiba City. Presently, the knowledge of advanced science and technology
held by university research institutions and other companies is being passed onto further
generations through the implementation of the “Future Science Development
Programme” through which junior and high schools in Chiba City are giving students theopportunity to experience drone and robotic technology. Maths has played an essential
role in technological advancement since the beginning of time. Chiba City recognizes theimportant of implementing a mathematical way of thinking and using technology insociety to solve social issues. Chiba City avails of AI technology to maintain roads in thecity through the automatic detection of road damage, in order to improve services for
citizens. To improve the prospects of possible future scientists who could play a roleinternationally, Chiba Municipal Chiba High School is a state designated ”Super Science
High School”. Through collaborative courses with universities and research institution,and team teaching by teachers in every subject, students at the school are working on
applied science and maths, pushing beyond the usual borders of these subjects bystudying team in combination with other subjects.
On a side note, the kanji for Chiba City is written using the characters “thousand” and“leaves”. The kanji for Chiba was first published 1200 years ago during the late Nara
period in the “Mannyoshu”, also known as the “Collection of ten Thousand Leaves”,
which is Japan’s oldest poetry collection. There are various theories as to the selection of
the name “a thousand leaves”, but one of the theories is that is it a description of lush
flora. I feel deeply moved by the connection between the name “Chiba”, which means“thousand leaves”, and mathematics, a language which can describe all things in theuniverse. To all the participants, you have all worked extremely hard over the past twodays. I have no doubt that you all put in a great deal of preparation for this event in order
to withstand intense pressure during the competition and represent your country at thehighest level.
I hope that you will all cherish the intercultural bonds that you have formed as a result ofparticipating in this competition. In conclusion, I would like to express my gratitude to all
those who were involved in organizing the International Mathematical Olympiad and I
hope that the actions of the participants will lead to the further progression of maths andin turn, society.
Thank you very much.

22

⿎ Farewell Message from
IMO2023 日本大会実行委員会委員長 数学オリンピック財団理事長 藤田 岳彦
Hello, everyone. Iʼm Takahiko Fujita, in charge of this Japan IMO. I declare the commencementof the closing ceremony. As I stated before during the Opening Ceremony, Iʼm confident that you
enjoyed mathematics, Japan, and international exchange. From now, the major role during the
Closing Ceremony is the medal presentation. It is a great moment where the outstandingachievements and efforts of contestants are recognized and celebrated. Thank you.
⿎ General review from（IMO2023 Closing ceremony 総評）
IMO Board President Prof. Gregor Dolinar, Ph.D.
Distinguished guests, honorable Mayor of Chiba, leaders, deputy leaders and the contestants.
The square edition of IMO is coming to an end, and at this point I would like to sincerely thankthe organizers who put a lot of effort and resources into making for the 64th IMO as perfect as
possible. The organizers have done a great job and on behalf of the IMO Board, and the entire
IMO community, I would like to say thank you very much. “Domo arigato gozaimasu” (どうもありがとうございます).
A few words to the contestants: First of all, congratulations to all the prize winners. You havedone an excellent job and you will receive the prizes and all the glory you have worked so hardfor. Enjoy the glory! Contestants, I am very well aware that some of you may be a little
disappointed. That is completely understandable - you are here because you love to compete, and
it is not great to miss an honorable mention because of a stupid mistake, to miss a medal of bronze,silver or gold for just one point, or maybe to even have 41 points out of 42, but you should not be
too disappointed. As I said at the opening ceremony, you are the best young people in yourgeneration in your country - so you are almost all the time the best in your schools, in yourregions, and in your counties. So, you are used to being on the top all the time. But you know, if
you are always the best, then you are in the wrong room. You have to find a room that will
challenge you and allow you to improve and grow. And I hope, I truly hope, that we can all agree
that at this very moment you are all in the right room. And for being here in this room, at
IMO2023, I congratulate you from the bottom of my heart. Bravo !
⿎ IMO2023 Closing remarks（閉会の挨拶）
IMO2023 日本大会実行委員会委員長 数学オリンピック財団理事長 藤田 岳彦
While not all contestants may have been able to win medals, I wonʼt forget you. Their presence
and participation in the IMO is already a remarkable achievement itself. So for all of you, it takes
great direction, skill, and hard work to reach the level competing on such a stage. So, all theexperience gained from this Japan IMO are sure to be invaluable for the future lives of allcontestants. So please, enjoy the farewell party. Thank you.
23

23

English (eng), day 1

Saturday, 8. July 2023
Problem 1. Determine all composite integers n > 1 that satisfy the following property: if d1 , d2 , . . . , dk
are all the positive divisors of n with 1 = d1 < d2 < · · · < dk = n, then di divides di+1 + di+2 forevery 1 ⩽ i ⩽ k − 2.
Problem 2. Let ABC be an acute-angled triangle with AB < AC. Let Ω be the circumcircle ofABC. Let S be the midpoint of the arc CB of Ω containing A. The perpendicular from A to BC
meets BS at D and meets Ω again at E ̸= A. The line through D parallel to BC meets line BE
at L. Denote the circumcircle of triangle BDL by ω. Let ω meet Ω again at P ̸= B.
Prove that the line tangent to ω at P meets line BS on the internal angle bisector of ∠BAC.
Problem 3. For each integer k ⩾ 2, determine all infinite sequences of positive integers a1 , a2 , . . .
for which there exists a polynomial P of the form P (x) = xk + ck−1 xk−1 + · · · + c1 x + c0 , wherec0 , c1 , . . . , ck−1 are non-negative integers, such that
P (an ) = an+1 an+2 · · · an+kfor every integer n ⩾ 1.

Language: English
24

Time: 4 hours and 30 minutes.
Each problem is worth 7 points.

English (eng), day 2

Sunday, 9. July 2023
Problem 4.

Let x1 , x2 , . . . , x2023 be pairwise different positive real numbers such that
√
(
)
1
1
1
+
+ ··· +
an = (x1 + x2 + · · · + xn )
x1 x2
xn

is an integer for every n = 1, 2, . . . , 2023. Prove that a2023 ⩾ 3034.
Problem 5. Let n be a positive integer. A Japanese triangle consists of 1 + 2 + · · · + n circles
arranged in an equilateral triangular shape such that for each i = 1, 2, . . . , n, the ith row contains
exactly i circles, exactly one of which is coloured red. A ninja path in a Japanese triangle is asequence of n circles obtained by starting in the top row, then repeatedly going from a circle to oneof the two circles immediately below it and finishing in the bottom row. Here is an example of aJapanese triangle with n = 6, along with a ninja path in that triangle containing two red circles.

n=6

In terms of n, find the greatest k such that in each Japanese triangle there is a ninja path containing
at least k red circles.
Problem 6. Let ABC be an equilateral triangle. Let A1 , B1 , C1 be interior points of ABC suchthat BA1 = A1 C, CB1 = B1 A, AC1 = C1 B, and∠BA1 C + ∠CB1 A + ∠AC1 B = 480◦ .
Let BC1 and CB1 meet at A2 , let CA1 and AC1 meet at B2 , and let AB1 and BA1 meet at C2 .
Prove that if triangle A1 B1 C1 is scalene, then the three circumcircles of triangles AA1 A2 , BB1 B2and CC1 C2 all pass through two common points.
(Note: a scalene triangle is one where no two sides have equal length.)

Language: English
25

Time: 4 hours and 30 minutes.
Each problem is worth 7 points.

Ⅵ Results and Awards 結果⚑

Summary

まとめ

GENERAL INFORMATION
Chiba, Japan IMO 2023, 2. 7.‒13. 7. 2023
Number of participating countries: 112
Number of contestants: 618; 67 ♀
AWARDS
Maximum possible points per contestant: 7 + 7 + 7 + 7 + 7 + 7 = 42
Gold medals: 54 (score Ƭ 32 points) Perfect score: 5 (score  42 points)
Silver medals: 90 (score Ƭ 25 points)
Bronze medals: 170 (score Ƭ 18 points)
Honourable mentions: 192
Mirzakhani Awards: 5※ 2023 日本大会及び歴代大会個人成績は「IMO ホームページ」に常時掲載⚒

Statistics

統計
P1

P2

P3

P4

P5

P6

Num (P# = 0)

26

202

396

86

219

555

Num (P# = 1)

19

100

102

100

29

11

Num (P# = 2)

67

6

7

32

174

36

Num (P# = 3)

9

62

23

8

52

4

Num (P# = 4)

9

20

8

4

4

1

Num (P# = 5)

6

7

6

1

13

1

Num (P# = 6)

8

6

3

3

9

4

Num (P# = 7)

474

215

73

384

118

6

Mean (P#)

5.845

3.162

1.256

4.717

2.417

0.275

Max (P#)

7

7

7

7

7

7

ç (P#)

2.227

3.050

2.320

3.000

2.568

1.004

Corr (P#, Sum)

0.677

0.780

0.708

0.801

0.746

0.457

0.422

0.271

0.576

0.383

0.125

0.482

0.520

0.412

0.311

0.377

0.502

0.480

0.512

0.193

Corr (P#, P1)
Corr (P#, P2)

0.422

Corr (P#, P3)

0.271

0.482

Corr (P#, P4)

0.576

0.502

0.377

Corr (P#, P5)

0.383

0.412

0.502

0.512

Corr (P#, P6)

0.125

0.311

0.480

0.193

26

0.306
0.306

34

Problem 1

Problem 2

600

600

500

500

400

400

300

300

200

200

100

100

0

0

1

2

3

4

5

6

0

7

0

1

2

Problem 3
600

500

500

400

400

300

300

200

200

100

100
0

1

2

3

4

5

6

0

7

0

1

2

Problem 5
600

500

500

400

400

300

300

200

200

100

100

35

0

1

2

3

4

5

6

7

3

4

5

6

7

5

6

7

Problem 6

600

0

4

Problem 4

600

0

3

5

6

0

7

27

0

1

2

3

4

⚓

Awarded Contestants

表彰選手【Gold】

Davit Kldiashvili

GEO

Chunji Wang

CHN

Robert Dragomirescu

ROU

Haojia Shi

CHN

Andrei-Giovani Chiriǎ

ROU

Junhwi Bae

KOR

László Bence Simon

HUN

David-Andrei Anghel

ROU

Damjan Davkov

MKD

Derek LiuUSA

Keyn-Hantz Edden Chew

SGP

Xingjian Liang

CHN

Mehmet Can Baştemir

TUR

Xinliang Zhang

CHN

Isaac King

UNK

Warren Bei

CANAlexander Wang

USA

Woojin Choi

KOR

Chunji Wang

CHN

Qiao Sun

CHN

Haojia Shi

CHNArjun Gupta

IND

Junhwi Bae

KOR

Atul Shatavart Nadig

INDDavid-Andrei Anghel

ROU

Ryunosuke Kitamura

JPN

Derek LiuUSA

Gyudong Lee

KOR

Rogelio Guerrero Reyes

MEX

Hao Xiang Gabriel Goh

SGP

Martin Bierbaumer

AUT

Jeff Lin

USA

Ruben Mason Carpenter

ESP

Eric Shen

USA

Juri Kaganskiy

GER

VietHung Pham

VNM

Panagiotis Liampas

HEL

Marin Hristov

BGR

Satoshi Kano

JPN

Andrei Moldovan

ROU

Jihoo Lee

KOR

Zian Shang

AUS

Omar Farid Astudillo Marbán

MEX

Zhicheng Jiang

CHN

Juan Mathius Tasayco

PER

Georgios Tzachristas

HEL

Wenhao Cheng

SGP

Cheuk Hei Chu

HKG

Worrawat Rungaramsin

THA

Ehsan Heidari

IRN

Chi-An Chang

TWN

Itamar Nir

ISRPolina Henyk

UKR

Tanoshi Furuya

JPN

Tuan Dung Hoang

VNM

Youngbeom Jin

KORWilliam Cheah

AUS

JerRen WongMAS

Anatole Bouton

FRA

Enerelt Delgerdalai

MNG

Sobhan Aram

IRN

Mathys Douma

SUI

Mohammadermia Ghaseri

IRN

Tayakorn Suwanich

THA

Yuchan Jung

KOR

En-Hua Chiang

TWN

Angelo Farfan

PER

Alex Chui

UNK

Radu-Andrei Lecoiu

ROU

Alex Zhao

USABarış Koyuncu

TUR

An Thinh Nguyen

VNMŞevket Onur Yılmaz

TUR

Luca Sartori

ITA

Chi-En Chung

TWN

Pavel Ciurea

ROU

Maximus Lu

USA

Matheus Alencar de Moraes

BRA

Matsvei Zorka

BLR【Perfect】【Silver】

28

36

Matvey Vylegzhanin

BLR

Nitiwit Sirimalaisuwan

THA

Rodrigo Salgado Domingos Porto

BRA

Hakan Gökdoğan

TUR

Paul Jakob Schmidt

GER

Felipe Klir

ARG

Boldizsár Mann

GER

Fidan Garayeva

AZE

Bernát Tarján

HUN

Ivan Tagarev

BGR

Rafael Kristoforus Yanto

IDN

Ara Mahdessian

CYP

Ananda Bhaduri

IND

Arvin Taheri

IRN

Siddharth Choppara

IND

Simone Foti

ITA

Avner Spira

ISR

Naoto Wakasugi

JPN

Assaf Yacouel

ISR

Victor Manuel Bernal Ramírez

MEXRaphael Dylan Dalida

PHIJohn Hedin

SWE

JeromeAustin Te

PHI

Raiymbek Baishuak

KAZ

Hadi Alaithan

SAU

Areg Mkrtchyan

ARM

Drew Michael Terren Ramirez

SGP

Márton Tamás NémethHUN

Jakub Šošovička

SVK

Chon Hou Ye

MACPatanasang Pinijpichitkul

THA

Eric Ransom Treviño

MEX

Melek Güngör

TUR

Aleksij Tasikj

MKD

Yu-An ChoTWN

Bas Capel

NLD

Thomas Kavanagh

UNK

Yan Xi Peh

SGP

Dinh Kien Nguyen

VNM

Meng-Che Hsu

TWN

Dhruv Basu

CAN

Kaixin Wang

CAN

Andrej Krčmar

BIH【Bronze】
Chams Eddine Abd El Ali Derreche

ALG

Leonardo Henrique Fakhreddine Maldonado BRA

Aghasi Darbinyan

ARM

Daniil Akimov

FIN

Cloris Xu

AUS

Chun Hei Yiu

HKG

SMA Nahian

BGD

Pietro Gualdi

ITA

Nujhat Ahmed Disha

BGD

Yasuo Hayashi

JPN

Angel Hristov

BGR

Paulius Aleknavičius

LTU

Ivan Korshunau

BLR

Filbert Ephraim Wu

PHI

Luís Felipe Pestana Giglio

BRA

Mateusz Gabzdyl

POL

Eduardo Henrique Rodriguesdo Nascimento BRA

Youkyum Kim

SAF

Haozhe Yang

CAN

Serdar Bozdağ

TUR

Aleksei Ganyukov

EST

William Thomson

UNK

Bronislav Shatil

EST

Ming Yang

CAN

Serge Bidallier

FRA

Marvin Mao

CAN

Oscar Fischler

FRA

Miron Yurkevich

KAZ

Tornike Beria

GEO

Kamo Mirakyan

ARM

Prodromos Fotiadis

HEL

Christopher Tran

AUS

Orestis Lignos

HEL

Mikita Shutro

BLR

Hok Lai Ng

HKG

Mikhail Raikhman

BLR

Namik Agić

HRV

Mohammadparsa Jafarnejady

IRN

Márton Lovas

HUN

Ofer Bogoslavsky

ISR

Rizky Rajendra Ananta Dewa

IDN

Mateja Vukelić

SRB

Pouria Rahmani

IRN

37

29

Enrico Zonta

ITA

Matija Skrt

SVN

Keisuke Koide

JPN

Mouhammad Ali Hourieh

SYR

Daande Groot

NLD

Adem Bizid

TUN

Mads Kok

NLD

Po-Shen ChangTWN

Al Waqas Mahmood Mohammed Al Khadhuri OMNSida Li

UNK

Konstanty Smolira

POL

Ozodbek Akhtamov

UZBAli Alramadan

SAU

Bozhidar Dimitrov

BGR

Mahdi Albaik

SAU

Erik Ježek

CZE

Muath Alqahtani

SAUŠtěpán Mikéska

CZE

Aleksandar VišnjićSRB

Aino Aulanko

FIN

Yevheniia Frankevych

UKR

Emanuel Tukač

HRV

Nguyen Thanh Danh Tran

VNM

Evelyn Lianto

IDN

Dinh Toan Khuc

VNM

Adhitya Mangudy Venkata Ganesh

IND

Vahan Baghdasaryan

ARM

Yotam Amir

ISR

Sizhe Pan

AUS

Carlo Baronio

ITA

Pierre Akin Dürrüoglu

BEL

Margus Smotrovs

LVA

Vuk Janković

BIH

Ansis Gustavs Andersons

LVA

Ervin Macić

BIH

Hylke Hoogeveen

NLD

Pavel Tsitou

BLR

Ahmed Raza

PAK

Felipe Makoto Shimamura Silva

BRA

Jose Rojas

PER

Samuel Rosiar

CZE

Rickson Caleb Tan

PHIDaniel Pham Nguyen

DEN

Stefan Šebez

SRB

Luna Skjernaa Mygind

DEN

Alisa Potomkina

UKR

Darío Martínez Ramírez

ESP

Zhan Dautov

KAZCharles Dai

FRA

Batyrkhan Sakenov

KAZGaëtan Dautzenberg

FRA

Vesselin Markovich

BGR

Florian Elbrandt

GER

Mirnes Fehrić

BIH

Leonard Kottisch

GER

Filippos Athos Chatzichristofi

CYP

Yung Ho Kwan

HKG

Michal Janík

CZE

Chong Ho Hsieh

HKG

Roger Lidón Ardanuy

ESP

Csilla Fülöp

HUN

Jordi Ferré García

ESP

Denis Tusca

ITA

Kristjan-Erik Kahu

EST

MargulanSharel

KAZ

Philipp Siegert

GER

Luis Eduardo Martínez Aguirre

MEX

Dionysios Petrakis

HEL

Nikola Cvetanoski

MKD

Fionn Kimber OʼShea

IRL

Iveel Arvis

MNG

Benedikt Vilji Magnússon

ISL

Saikhanbileg Tsogtgerel

MNG

Ori Frankel

ISR

Yanniek Nitescu

NLD

WangIok Lin

MAC

Bufan Zhao

NZL

Kuok WaiU

MAC

Sebastian Lozada

PER

Min Heng Tan

MAS

Michał Piotr Lipiec

POL

Mateo Iván Latapí Acosta

MEX

Rafael Martim Tavares Inácio

POR

Nursoltan Khavalbolot

MNG

Bora Olmez

SUI

Lance Bakker

NLD

Eliška MacákováSVKDavid Strømme Eikeland

NOR

30

38

Krzysztof Salata

POL

Jalil Huseynov

AZE

Martin Kopčány

SVK

Guillem Beltran Cerezuela

ESP

Selim Halykov

TKM

Auguste Ramondou

FRA

Vladimir Rogovskiy

KAZ

Guram Matcharashvili

GEO

Youcef Kenane

ALG

Tamar Peikrishvili

GEO

Hamlet Petrosyan

ARM

Sebastian Chase

HKG

Md Shahriar Hossain

BGD

Janko Bušelić

HRV

Iliyas Noman

BGR

Ayman RiadSolh

MAR

Lorenzo Sarria

COL

Wei Jie Goh

MAS

Benedek Nádor

HUN

Alin Popescu

MDA

Archit Manas

IND

Jordan Juarez

PER

Hitihami Mudiyanselage Mihiru Anushka Bandara LKA

Alvann Walter Paredes Dy

PHI

Alfrēds Saročinskis

LVA

Felix Xu

SUI

Kwong WengLoh

MAS

Olimdzhon Tukhtarov

TJK

Drago・Port

MDA

Kseniia Drozdova

UKR

Piotr Maksymilian Miernik

POL

Anvarbek Sadulloev

UZB

Minkyum Kim

SAF

Andrija Živadinović

SRB

Jonah Osterwalder

SUI

Mohamed Wacyl Meddour

ALG

Erik Hedin

SWE

Martín Lupin

ARG

Thammarak Korsakulthum

THA

Ignacio Naguil

ARG

Sidharth Puthiyedathu Suresh

UAE

David Buchmaier Bofill

AUT

Volodymyr Chub

UKR

Anar Mehdiyev

AZE

Hanks Chong

UNK

Mirhabib Asgarov

AZE

Robin Antoine

BEL

Luka Sebbag

BEL

Benjamin Mujkić

BIH

Debapriya Saha Roy

BGD

Mateo Lizcano

COL

Axel Dobloug

CYP

Gabriel NajmiasLang

CRI

Tereza Černá

CZE

Aleksandre Korkotashvili

GEO

Xavier Díaz Austrich

ESP

Lara Semeš

HRV

Ervin Ivanov

EST

Evan Nathanael

IDN

Ivane Kuljanishvili

GEO

Tomas Babelis

LTU

Axel Giovanni Hartanto

IDN

Dan Cernatinschi

MDA

Joshua Marvel Solomon

IDN

Nikola Spirovski

MKD

Fedor Korniiash

KGZ

Tenuunsaikhan Batlkhagva

MNG

Pijus Šapnagis

LTU

Edvard Walde Heimdal

NOR

Chong Un Un

MAC

Mohammad Nur Casib

PHI

Zakariyae Derro

MAR

Adam Džavoronok

SVK

Jan Stojanovski

MKD

Viktor Imrišek

SVK

Erkhesbold Ochirkhuu

MNG

Saria Ramadan

SYR

Kevin Francisco Aquino Díaz

PAR

Ivan Bortnovskyi

UKR

Robert Soboński

POL

Anvarbek Rakhmatov

UZB

Jared Slater

SAF

Federico Crovara

ARG

Abdulrahman Nassief

SAU

Georg Weisbier

AUT

Qinxi Yu

SGP

39

【Honorable Mention】

31

Matej Bachniček

SVK

Tsovak Yegoryan

ARM

Katarina Grilj

SVN

Dominik Pultar

AUT

Muhammad Alhomsi

SYR

Panagiotis Chatzikostas

CYP

Mashrafdzhon Inomov

TJK

Aleksander Karpov

EST

Hamza Allaberdiyev

TKM

Derek Samir Funez Estrada

HND

Omar Cherif

TUN

Batugahage Don Lasitha Vishwajith Jayasinghe LKA

Behzod Maksudov

UZB

Ramona Poreitere

LVA

Jan Strehn

AUT

Adrians Piliksers

LVA

Jitendra Barua

BGD

Marius Cerlat

MDA

Harun Alibegović

BIH

Robert Barbu･a

MDA

Carlos Andres Pozo Vargas

BOL

Egor Georgievskii

MNE

Theodor Boaz Pedersen

DEN

Ivar Lee Fevang

NOR

Thirukkumaran Theiventhiran

LKA

Swikriti Acharya

NPL

Constantin Babuc

MDA

Eidrian Lian Perez Gonzalez

PAN

Mohamed Mohamed Lemine Taleb

MRT

Salvi Mucyo

RWA

Jun Yang (Michael) Ma

NZL

Vukašin Pantelić

SRB

Tomás Faria

POR

AmirSoussi

TUN

Hugo Bruwer

SAF

Rasulbek Gafforov

UZB

Ivan Pouly

SUI

Dawn ChenNZLErik Červek Roškarič

SVN

Uriel Digestani

ARG

Ivar Ängquist

SWE

Iris Xu

AUS

Sirawit Pipittanaban

THA

Maia Reffs Vistisen

DEN

Rahym Agamyradov

TKM

Seán Hallissey

IRL

Davut Muhammetgurbanov

TKM

Nurtilek Duishobaev

KGZ

Eric Liang

NZL

HibaEl FarchiouiMAR

Abdennacir Boufedjighen

ALG

Soe Thway Ko

MMR

Farrukh Asadov

AZE

Gvozden Lapčević

SRB

Luis André Villan Gabriel

BOL

Aadi Sinha

UAE

Alejandro Campos Rojas

CRI

Erik Kërçiku

ALB

Carlos Shum Apuy

CRI

Andreas Arnfred Nielsen

DEN

Kyriakos Tsiannis

CYP

Ian Bobrus

KGZ

Aidin Asankadyrov

KGZ

Yassir Sbai

MAR

Ngou Hin Cheang

MAC

Eyad Alqatari

SAU

Yasser Abouseir

MAR

Lenart Dolinar

SVN

Vebjørn Holm-Gjerde

NOR

Mehrubon Sitamov

TJK

James Jia

NOR

Facundo Méndez

URY

Moied Baleg

SAF

Sirio Dafa

ALB

Enrique Adonay Hernández Rafaelano

SLV

Roberto Adum

ECU

Hugo Trebše

SVN

Jussi Marttinen

FIN

Allayth Shahet

SYR

Kristian Latvanen

FIN

Eraj Sabirov

TJK

Siiri Roschier

FIN

Mauro Akerman

URY

Stella ČoloHRV

Sukhrob Khalelov

UZB

Emily Wolfe

IRL

Ahmed Adnane Meddah

ALG

Tilek Askerbekov

KGZ

32

40

Eldar Iskanderov

Boning Dai

NZL

Chandhopama Thidas Bandara Wanasinghe LKA

Adrian David Frauca Arenas

PAN

JiaHerng Chuah

MAS

Nirvana Rosabella Marrero Tiodang

PRI

Branko Jangelovski

MKD

Samuella Kwizera

RWA

Haotian Wang

NZL

Yian Xu

SAF

Maryorie Damaris Cabrera Silvas

SLV

Fernando Andree González MeléndezSLV

Jiachen Mi

SWE

Batyr Ovezmyradov

TKM

Olle Rehnquist

SWE

Oussema Soussi

TUN

Abdulwahab Ozoun

SYR

Siyuan Lu

CHI

Yacine Dallil

ALG

Toomas Herodes

ESTPaul Hametner

AUT

Daniel Slivinskiy

FIN

Zhiyi Luo

BELÍsak NorðfjörðISLDavid Sompero Mendoza

BOL

Leonhard Hasler

LIE

Matias Nova

CHI

Michèle Voncken

LUX

Alberto Lobo-Guerrero

COLSong Pok Hong

MAC

Theofanis Orfanou

CYP

Aymen Hajifi

MAR

Konstantinos Konstantinidis

HEL

Muhammad Daniyal

PAK

Sithija Abhishek Kotuwewatta

LKA

Jorge Liu Luo

PAN

Jurgis Kemeklis

LTU

María José Ortiz Benítez

PAR

Benas Raišutis

LTU

Ariel Alejandro Insaurralde Aldana

PAR

Isaac Dahir Rodríguez Gutiérrez

NIC

Tobías Santiago Valdez Caballero

PAR

Mina Johanne Heier

NOR

Edmond Iradukunda

RWA

Tiago Miguel Gomesde Sousa

POR

Kaja Rajter

SVN

Xingyu Zhu

POR

Anisa Burieva

TJK

Haydar Qassem

SYR

Aweb Othmen

TUN

Tobías Rodríguez

URY

Juan José Martínez Barreto

VEN

Ibrahim Karimli

AZE

Ted Qamo

ALB

Akram Zakine

BEL

Nea Metohu

ALB

Marvin Mario Martinez Nuñez

BOL

Donato Ofi Moakofhi

BWA

Juanita Giraldo

COL

Matthías Andri Hrafnkelsson

ISL

Sergio Manuel Baldares ArceCRI

Jokūbas Jasiūnas

LTU

Carlos Manuel Navarro Mora

CRI

André Filipe Dourado Pinheiro

POR

Karla Yisel Ramírez Garcell

CUB

Lovre Pazinović

HRV

Kirill Zolotuskiy

ISL

Asia

Fidan Garayeva

Hrafnkell Hvanndal Halldórsson

ISL

Australasia

Nujhat Ahmed Disha

Edi Berisha

KSV

AfricaHiba El Farchioui

Orges Ajvazi

KSV

EuropeAlisa Volkova

Tobias Marxer

LIE

America

Maryorie Damaris Cabrera Silvas

Shithila Vibheetha Mahabaduge

LKA

Petr Gabuniia

LVA

Leia Mayssa MasyerinMAS

Hsu Wutt Yee Lin

MMR

José GabrielRivas Rivera

NIC

41

KGZ

【Mirzakhani Awards】

33

Ⅶ Information & Annual Regulations 通知と規則⚑

Information for Contestants

選手への通知Information for Contestants
The timings
The IMO 2023 contest will be held in Chiba,
Japan. The contest takes place on
Saturday 8. and Sunday 9. July 2023.
The contest is scheduled to start at 9:00 am andlasts 4 hours 30 minutes. Each day, contestants
are given three problems in up to threelanguages of their choice. At least one of theselanguages must be one of the official IMO
languages (English, French, German, Russianand Spanish).

entire exam. If you want to leave your desk
because you need to go to the toilet, or because
you want to finish the contest early, you mustfirst consult the invigilators (use the green or
red cards as described below).

What you may bringContestants must bring their IMO badge with
their name and photograph on.

On your workplace
Do not open the Day Folder or envelope before
you are instructed to do so.

Contestants should bring their personal writing
and drawing instruments such as pens, pencils,
erasers, pencil sharpeners, rulers andcompasses into the examination room.

On your workplace, you will find:•In a closed envelope: the contest
problems in up to three languages aspreviously requested• An instruction sheet•Three Question and Answer forms for
submitting a question to the Jury
•Five colored cards:
⿝Grey: to request more paper
⿝Orange: to submit a question to theJury (during the first 30 minutes
only)⿝Blue: to request water
⿝Green: if you need to go to thetoilet (not during the first or last 30
minutes)⿝Red: if you need help or want tostop working early (not during thelast 30 minutes)•The Day Folder which contain thefollowing materials:
⿝15-20 sheets of paper (Solutionform) to do your rough and final
work⿝Three Problem Folders with a
specific problem number printed
on: Problem 1, 2 and 3 for Day 1,
and 4, 5 and 6 for Day 2. Eachfolder is to collect solution sheets
for its specific problem

The following is not permitted:
Calculators, mobile phones, watches (anykind), electronic devices, protractors of any
kind including set squares with protractor
markings, briefcases, backpacks, toys, books,
notes, tables, papers or any other writtenmaterial.
You may also bring your personal food or
drinks (provided they do not make noise when
consumed) and, if desired, a small talisman(small enough so as to fit into one hand). Any
personal utensils that you wish to bring into
the contest room should be inside thetransparent plastic bag that is given to you on
arrival in Chiba.

The workplaces
The exams take place in Makuhari Messe.
You will be guided by the invigilators to yourlabelled desk according to a seating plan. You
will not be allowed to enter without yourname badge. Please check that your desk andthe folder on your desk are indeed marked
with your name and your contestant code.
Once seated, remain seated quietly during the34

42

Fill in your name, contestant code,
problem number (so only one problem
on a sheet of paper) and page number
on each answer form as you use it.
You must work on your own and submit
your solutions in your own language.
Your work will be scanned and copiedin black and white, so please use black ink
or a very dark black pencil.

Announcements
During the contest the elapsed time will bevisible throughout the contest hall.
The following main announcements andcommunications will be made during thecontest:
Before the contest: “Remain seated quietly anddo not open the Day Folder or envelope before
you are told to do so.”Questions to the Jury
During the first 30 minutes of the contest, you
may submit written questions to the Jury.
These should be written in your own languageon the question form provided. Once yourquestion is ready, raise your orange card andan invigilator will collect the Question andAnswer form and send it to the Jury. The Jurywill decide whether the question will beanswered, and if so, how; afterwards theanswer will be communicated back to you.
Depending on the number of questions, thismay take some time.

At the beginning of the working time: “Youmay now open the Day Folder and envelopeand start to work. You have the opportunity to
ask questions to the Jury in the first 30
minutes.”
After 25 minutes: “You have 5 minutes left to
ask questions to the Jury.”
After 30 minutes: “The time to ask questions
to the Jury is over.”After 3 hours 45 minutes: “You have
45 minutes left to work, but only 15 minutes to
use the toilets. You may not leave the room inthe last 30 minutes.”

Other needs or requests
If you need more water, raise your blue card.

After 4 hours: “You have 30 minutes left towork. You may no longer leave the room.”

If you have to go to the toilet, show your green
card (not during the first or the last 30 minutesof the contest). You will be shown which setof toilets to use.

After 4 hours 25 minutes: “You have
5 minutes left to work on the problems.”

In case of emergency or illness raise your red
card to receive help.

After 4 hours 30 minutes: “Please stop
working immediately. Put your solution sheets
into the Problem Folders. Then put all three
Problem Folders into the Day Folder. Pleasestay seated in silence.”

At the end of the exam
Once the end of the examination is announced,
stop writing immediately. Sort your work by
problem number and put the solutions for eachproblem into the appropriate problem folder.
Put the three Problem Folders, and only those,
inside the Day Folder. Leave the Day Folder
closed on your table and remain silent andseated until the invigilators have collected all
the folders.

Once all the scripts are collected: “Please stayseated until an invigilator tells you to leave theroom. Leave in silence by the door you camein. Please take all your belongings with you.”

Do not put any blank sheets inside the Problem
Folders. Unused blank sheets should be left on
the table. Used paper that you do not want tosubmit should also be left on the table and will
be discarded. For more information on what to
do at the end of your exam, check the rules on
how to submit your work.

Writing your solutions
Write your solutions and rough work on theanswer forms. If you need more paper, pleaseshow your grey card. An invigilator will give
you five more sheets of paper.
Do not write on the back of the paper.

43

35

Early termination of the contest
In case you finish your work during the first
four hours (before the last 30 minutes areannounced) you may show your red card to tellthe invigilators that you have finished and you
want to leave the room. After leaving theexamination room you will not be allowed
to return to it.

The organizers of the IMO 2023 wish you
good luck!
Hiroki Kondo
Chief Invigilator

During the last 30 minutes you cannot leave
the exam hall before the regular work period isover; if you finish during this period, wait
quietly in your place until the end. Also, youwill not be allowed to leave the room during
the first 30 minutes.
What to take out of the room
You are allowed to take the contest problems
with you (unless you leave early). Apart from
this, you are allowed to take out of the room
only the materials that you brought in yourplastic bag. Do not take with you any blank or
written answer sheet, Question & Answer
form or colored card.
Improper behavior
In the interest of a successful IMO 2023,
contestants are expected to work quietly
without disturbing others, and of course
respect the obligation to work on their own.
They need to follow these instructions andrules. In case of violations, the Chief
Invigilator may issue a warning, reportincidents to the Jury for further action, or takeother suitable action to maintain the integrityof the competition.
Fire alarms
In the unlikely event of a fire alarm going off
in the building, please sit in silence and wait
for the invigilators to tell you what to do.
Earthquake
Earthquakes often occur in Japan.
Buildings are designed to withstandlarge earthquakes.
Jumping out of a building in a hurry isvery dangerous. Please stay there.
In the case of a small earthquake,the examination continues as is.
In the case of a large earthquake,chief invigilator will tell you to suspend
the examination and hide under your desk.

36

44

⚒

Regulations of the 64th International Mathematical Olympiad 第 64 回 IMO 規則
January 2023

All deadlines (times and dates) are at 22:59 UTC (Japan is in UTC + 9 all year). All sums ofmoney mentioned are denominated in Yen.
See also general regulations, https://www.imo-official.org/documents/RegulationsIMO.pdf⚑．The Host City for the 64rd International Mathematical Olympiad (IMO 2023) is Chiba, Japan.
The main site is Makuhari messe and APA Hotels&Resort Tokyo Bay Makuhari. The
leadersʼ site (until Sunday July 9th 2023) will be Hotel Nikko Narita. From Monday July 10th
onwards, the whole IMO will be based at the main site.
⚒．The Host Organization for IMO 2023 is The Mathematical Olympiad Foundation of Japan.
⚓．The official programme for Leaders and Observers A begins on (arrival day) Monday July
3rd 2023 and ends on (departure day) Thursday July 13th 2023. The shortlisted problems
will not be released before Monday July 3rd 2023.
⚔．The official arrival day for members of the IMOB is Sunday July 2nd 2023. Leaders andObservers A may arrive on Sunday July 2nd 2023 on payment for the extra day of JPY 30,000
for a single room for each person, and JPY 20,000 for shared accommodation.
⚕．The Official Programme for Deputy Leaders, Contestants and Observers B and C begins on(arrival day) Thursday July 6th 2023 and ends on (departure day) Thursday July 13th 2023.
⚖．The Contest days for IMO 2023 will be Saturday July 8th and Sunday July 9th. All
Contestants must have been born on or after July 2nd 2003.
⚗．Participation of countries and territories must be confirmed online no later than Wednesday
February 15th 2023.
⚘．Registration of Leaders, Deputy Leaders, Observers and the number of Contestants must becompleted online no later than Friday April 21st 2023.
⚙．Registration of Contestants must be completed online no later than Wednesday May 31st2023.
10．Registration of travel details of Participants and Observers must be completed online nolater than Thursday June 15th 2023.
11．The official arrival and departure sites for IMO 2023 are the following preferred locations:
Narita Airport and Haneda Airport.
12．Accommodation at both sites is normally in shared rooms. Leaders will move to the main siteon Sunday July 9th 2023. Leaders may apply for a single room upgrade at both sites (for afee). The deadline for receipt of such an application is Friday April 21st 2023. Since extra
accommodation is limited, full payment in cleared funds of the following charge must be45

37

made by Friday May 19th 2023. be made by Friday May 19th 2023.
•Single room upgrade for a Leader: JPY 100,000.
Applications received without the full payment of the charges will be rejected. No refunds
will be given.
13．Applications for Observers to accompany the participants must be made by Friday April
21st 2023. Observers A may apply for a single room upgrade at both sites (for a fee). The
deadline for receipt of such an application is Friday April 21st 2023. Observers B and C may
also apply for upgrades to single rooms at the main site (for a fee). Since extra
accommodation is limited, full payment of the following charges must be made in cleared
funds by Friday May 19th 2023:•Deputy Leader: Single room upgrade : JPY 70,000.
•Observer A (accompanying the Leader): JPY 300,000 (shared accommodation).
•Observer A: JPY 100,000 for an upgrade to single room.
•Observers B and C: JPY 200,000 (shared accommodation).
•Observers B and C: JPY 70,000 for an upgrade to single room.
Applications received without full payment of the charges will be rejected. No refunds will
be given.
14．Proposals for problems must be received by Sunday April 2nd 2023. Proposals must be
submitted via the portal at the IMO official website.
15．Countries that need an official invitation in paper form via (old style) mail, should inform _info@imojp.org before Saturday April 1st 2023.
16．Each Leader must ensure that every participant from their country has appropriate travel
and health insurance, including Covid related costs, for the relevant period around IMO 2023.
Expenses for any quarantine hotel on arrival must be paid by each individual participating
country. It is recommended to purchase flexible tickets so that flights may be changed forany reason (including Covid).
17．Health policy̶. During the IMO, all participants must adhere to the organizerʼs Covid
protocol, including testing for Covid. The current Covid policy in Japan is URL LINK.
17：森田、小島・前田、各先生共同担当
18．Leaders must ensure that all child protection measures which are legally enforced in theircountry of origin are correctly observed.
19．For each student less than 18 years old, Deputy Leaders must bring legally notarized letters,
signed by the parents (or legal guardians), which state that, in case of medical emergency,
the Leader, Deputy Leader or Observer should have the right to approve any necessary
medical procedure at the IMO. This letter (in English) should state which of the Leader,
Deputy and any Observers is (or are) in loco parentis (i.e. they have the legal role of parentsof the children aged under 18 in their team during IMO 2023).
38

46

20．IMO General Regulation 1. 10 concerns bullying, discrimination and harassment. This
regulation is in addition to the laws of Japan. The laws of Japan take precedence over General
Regulation 1.10, and allegations of serious misconduct will be reported to the police.
21．Team members of Country X should normally be citizens of Country X, but genuine longterm foreign residents who are not citizens (and who are being educated in Country X) arepermitted to be in the IMO team of Country X provided that the student will spend at least
three full academic years being educated in Country X. Such a foreign education must be fora bona fide reason (e.g. family location). Note that IMO tourism is not permitted: a student
may not attempt the final selection examinations of more than one country in a given IMO
year. A student who changes their country of residence artificially in order to attempt toqualify for the new countryʼs IMO team, is in fact not allowed to represent. Members of adelegation of any country who conspire to subvert (or attempt to subvert) IMO selection
regulations risk suspension from IMO participation. Such a suspension will be reported to
the Ministry of Education of the country concerned. (Move 21 to General Regulation at the
Joint Meeting in Chiba)
22．The host country can invite 6 students from suspended countries to compete remotely as
private individuals (not as a team). The exact protocol for their participation (translations,exam, marking etc.) will be provided in due time.
23．Remote sitting may be permitted but only when Force Majeure makes it impossible to travel
to Japan (e. g. full Covid lockdown, armed conflict...). Note that financial reasons are notenough. Countries who wish to apply for permission to sit remotely should send evidence as
to why they cannot travel to Japan. A joint IMOB-Japanese Committee will review theevidence and in well founded cases may allow remote sitting. Note that decisions will not bemade before the deadline for submitting contestant names (i.e., May 31st).
24．Countries which and people who have been given explicit permission by the Japaneseorganizers and the IMO Board may sit IMO2023 in their own countries or territories. Suchexams must take place in an Exam Centre under the supervision of an independent IMO
Commissioner approved by the IMOB. The Exam Centre must be continuously monitored
both by the IMO Commissioner and by recording cameras. The recordings must be kept safe
until the Ethics Committee approves their destruction. The IMOB and Ethics Committee
reserve the right to view these recordings.
The Exam Centre should mimic the conditions of a normal IMO Exam hall. If social
distancing is necessary, then the conditions in the Exam room must comply with local
regulations and guidelines.
Unless there is a special arrangement, the remote exams must take place at exactly thesame time as at IMO2023 in Japan. Appropriate language versions of IMO2023 exam
papers will be provided to the IMO Commissioner as PDFs before the start of each exam.
47

39

First half-hour Questions of clarification can be answered without reference to Japan withthe help of guidelines which will be supplied. Photos or scans of all the written questions
and the corresponding written answers must be sent to the Ethics Committee by email at
the time the answer is given. The Ethics Committee may deduct marks from students ifthey judge that unfair assistance has been given. Answers should be given according to
the guidelines where possible. In addition to the questions in local languages, translationsof question and answers into an official IMO language should be supplied.
After each Examination, scans of all work should be uploaded for coordination which will
be conducted remotely from Japan by the IMO2023 coordinators.
Note that, in accordance with General Regulation 6.5, participating countries which senddelegations to attend IMO2023 in person will have privileged access to the IMO2023
shortlist before IMO2024. Remote attendance is not sufficient.

40

48

Ⅷ Goods•T-shirt•Cap•Backpack with handle•Folding umbrella•Ballpoint pen and Report paper

41

•Report paper (front)•Key ring (panda)•Mug•Water bottle•MedalGold

SilverBronze葛飾北斎 富嶽三十六景「神奈川沖浪裏」からデザイン

42•Supplementary prize(crystal glass)Ⅸ Summary of Operations
１ Operation and Management
IMO2023 Executive Committee
Led by Dr. Takahiko Fujita, Executive Committee Chair (JMO President), Dr. Yoshiaki
Maeda, Deputy Executive Committee Chair, Mr. Yasuharu Asai, JMOB Secretary General,
and Dr. Yasuo Morita, former JMO President (IMOB member), the Executive Committee
began full-scale preparations in September 2018, about five years ago, and held 33 Executive
Committee meetings before the IMO2023. During this period, we met with the Corona virus
disaster and major changes in the world situation. It was difficult to foresee the future, but we
received subsidies from the government (JST) and support from sponsor companies andindividuals in Japan and abroad. The committee would like to express
our gratitude to all those involved for making the conference a success.

Short-listed Problems and Solutions
The Problem Selection Committee consisted of 14 up-and-coming researchers, seven fromJapan and seven from overseas, led by the chief, Dr. Tetsuya Ando. All of the committee
members were familiar with the activities of IMO (domestic members are also in JMO) andhad a keen eye for problem selection. Their work, backed by their expertise, was the first step
toward the success of the IMO 2023, given the tight schedule of the IMO 2023.

Coordination
A total of 65 IMO/OB/OGs, 31 from Japan and 34 from overseas, served as coordinators for
IMO2023. All of them were up-and-coming young researchers, graduate students, andundergraduates, and were the most experienced group closest in age to the contingent. It wasalso very encouraging to have eight senior coordinators, one from Japan and seven fromoverseas, who assisted in the fair and smooth progress of the program as coordinatingsupervisors.
Their sense of duty as coordinators, whose role in scoring and adjusting the scores would
determine the outcome of the contest, kept the coordination meetings full of heated but
professional discussions.

Information Technology
The System Committee began its preparations around August 2022, about a year before thecompetition. At the end of 2022, the committee opened the IMO Japan website to publicize
the event and contribute to raising public interest. The core system for the operation of the43

competition, such as the identification of participant information, the contest progression,and information processing, was fully entrusted to Dr. Matjaz Zeljko's team, which wascommissioned by the IMO. Under the supervision of Executive Committee member, Dr.
Kouki Taniyama and his team, this systematic program was the driving force behind thecompetition operations. In addition, at the Narita and Makuhari venues, the day's scheduleand communications were displayed on large screens (located at the reception desks and otherlocations). This was very effective in improving the efficiency of information sharing, as manydelegation leaders, officials, and contestans were able to see the information as they passedby.

Jury Meeting
The Jury Committee, consisting of leaders of the delegations and the observers from eachcountry, began selecting contest questions from the Short-listed Problems for the first half ofthe competition. The task of selecting six good questions from the Short-listed Problems andtranslating them into their native languages in a short period of time was always a difficult
one, but the experienced members of the team accomplished the task. In addition, themedalists were decided accurately and smoothly at the Final Jury Meeting just before theawards ceremony. These tasks were the result of international cooperation by a strong groupof experts.

Examinations
The total number of contestants was 618 from 112 countries/regions, the largest number ever.
The preparation and administration of the examination was led by Dr. Hiroki Kondo of the
IMO 2023 Executive Committee. The examination was supervised by Dr. Tetsuya Ando of
Chiba University, who contributed to the extremely smooth preparation and execution of theexamination by 39 undergraduate and graduate students of Chiba University. In addition, thisyear's competition was the first in Japan to adopt a method of reading in PC data from ascanner instead of photocopying, thanks to a system improvement by Dr. Matjaz Zeljko, in
preparation for the post-examination marking. The students who supervised the examinations
also played an active role in this work, learning the process in a short time and making surethat the first attempt went smoothly. It should be noted that the two Japanese coordinators,
who are IMO alumni, were able to successfully complete this large-scale test because of theirleadership and supervision of the test administrators from the preparation on the day before
the test to the end of the test. In addition, six Russians participated online in their individual
capacity.

44

Volunteers
Forty-seven volunteers from the Chiba Convention Bureau participated in this year's
convention through the Chiba International Center, the host of the convention. In addition,
14 people from universities and other organizations also volunteered to support theconvention. The volunteers welcomed the participants at the airport, registered them at thehotel reception desk, and provided information at the various venues. The committee would
like to express my sincere gratitude to all of them.

GuidesDuring the period of the Olympiad, 119 members of universities and graduate schools inJapan served as guides for the 112-country delegation, working closely with the contestantsin their respective countries from arrival, registration, opening ceremony, contests, TDL,
excursions, closing ceremony, farewell party, to departure. They worked together and guided
us with dedication. All the guides demonstrated their language skills and hospitality, and someof them commented that the week went by quickly and was a very fulfilling experience.

Staff
A total of 100 staff members worked at the convention office, travel agencies, and otherorganizations. The environment was different from that of the previous convention in Japan(July 2003), which was held 20 years ago, and almost no one had direct experience of the IMO.
Many participants, especially those from overseas, commented that it was a “good convention.”

2

Ceremony

Opening Ceremony
The opening ceremony was held at 13:30 on Friday, July 7 at the International Conference
Hall of Makuhari Messe. The program proceeded as follows: Entrance of athletes → Opening
ceremony → Opening remarks → Attractions → Introduction of participating countries →Closing remarks → Exit.
The opening address was delivered by Ms. Keiko Nagaoka, Minister of Education, Culture,
Sports, Science and Technology, Dr. Gregor Dolinar, IMOB President, and Mr. Takeshi
Soeda, President of Gibraltar, Organizing Committee Chairman. Also in attendance wererepresentatives from 2 foreign embassies, 27 people from 15 organizations and companies, 5
people from JST, and 11 parents of the Japanese contestants. The opening ceremony featured
taiko drumming, and the attraction was a musical performance. The taiko drumming and45

music were performed live, and were very effective in enhancing the atmosphere of the
opening ceremony.

Closing Ceremony
The Closing Ceremony was held on Wednesday, July 12 at 14:00 at the International
Conference Hall of Makuhari Messe.
The program proceeded as follows: Entrance → Opening (Digest of the Convention VTR) →Opening Remarks → Awards Ceremony → IMO Flag Conferral Ceremony → VTR tointroduce the next host country → Closing Remarks → Exit.
Opening remarks were made by Mr. Shunichi Kamiya, Mayor of Chiba City, and Mr.
Takahiko Fujita, President of the Mathematical Olympiad Foundation. Other participants
included 2 from the Ministry of Education, Culture, Sports, Science and Technology, 2 from
Chiba City, 6 from foreign embassies, 32 from 19 organizations and companies, 4 from JST,
10 parents of Japanese athletes, and 27 parents of athletes representing foreign countries.
The medal presentation ceremony was a great honor for the athletes, with the cooperation ofmany people, including representatives of sponsor companies, foreign embassy staff, guests,
and executive committee members, who served as award presenters.

3

ContestThe contest was held at Makuhari Messe Exhibition Hall for two days on Saturday, July 8 andSunday, July 9 (Sun.). Preparations for the event began in the afternoon of Friday, July 7, theday before the contest, and were carried out in parallel with the opening ceremony at theInternational Exhibition Hall. The simultaneous preparation was very tight in terms of staffing,
but with the help of tutors who had experience as athletes, we were able to proceed without
delay. Due to the time differences between participating countries, a few of the contestants
felt ill for a while during the contest, but the illnesses were mild, and they were able tocontinue with the contest. Despite the extremely hot weather, the air conditioning in thevenue was appropriately adjusted, and the contest was able to proceed extremely smoothly
overall. This year's contest marked the first time in Japan that the conventional method of
copying and grading answers was adopted, using a scanner to read the answers into a PC. Thisreading process was carried out after the answer sheets were collected on both the first andsecond days. Although this was a first attempt, it went smoothly, thanks to prior discussions
among the parties involved.

46

4

EventsTour of the leaders
On Saturday, July 8, the first day of the contest, the tour was divided into two choices: “NaritaSanshinshoji Temple” and “Sawara City (Tadataka Ino Memorial Museum, Mitsubishi
Museum, boat tours, etc.),” both of which relate to Chiba Prefecture, the host of the contest.
The tour offered visitors a taste of Japan's rural tourist destinations with an atmosphere notfound in urban areas.

Jane Street Hub
A community area was set up on the first floor of Makuhari Hall from Thursday, July 6 toTuesday, July 11 during the convention as a place for contestants to interact with each other.
The community service provided a relaxing space where mathematical discussions could beexchanged and games could be played, which was different from the tense atmosphere of thecompetition.

Sponsors Booths
From Thursday 6th July to Wednesday 12th July, sponsors' booths were set up at the Sky
Banquet on the 46th floor of the Makuhari APA Hotel and on the first floor of the Tokyo Bay
Makuhari Hall. Exhibiting companies included FUJITSU, Gibraltar, Arithmer, Huawei,
Quantco, IBM, Karakuri and Yahoo. Many players showed great interest in the booths of theseworld-class companies and spent a lot of time there between contestants.

Sports Event
On Sunday 9th July from 3pm to 6pm, Tuesday 11th July from 9am to 5pm and Wednesday
12th July from 9am to 12pm, the grounds and tennis courts of Kanda University ofInternational Studies in Makuhari were available for participants to enjoy football and tennis.
Due to the extremely hot weather, staff and guides were on hand to help with rest andhydration, and a nurse was also on standby.

steAm Culture Festival
steAm Ltd, of which Executive Committee member Nakajima is CEO, held workshops at
Makuhari Hall from 9 to 11 July under the theme "Japanese Culture x Mathematics" with theaim of introducing Japanese culture. The programme included "Tea Ceremony - Urasenke","Furoshiki", "Mosaic Puzzle", "Origami" and "Mathematics and Music". Visitors were able toexperience the spirit of Japan and showed interest in the unexpected connection with amathematical viewpoint through origami (paper folding), furoshiki (patterns and wrapping)47

and puzzles (patterns of combination). The music department helped to unify the venue withmusical performances and Bon Odori dancing at the farewell party.

Jane Street Hub - Alumni/Contestant's Meeting Space
The Executive Committee set up a space on the first floor of Tokyo Bay Makuhari Hall from
July 6 to July 11, from 9:00 to 21:30, for IMO alumni and contestants to meet and interact. It
was a valuable opportunity for graduates to meet each other and renew old friendships after along absence.

The Group Tour for Teams
The tour was divided into two days, with a visit to Tokyo Disneyland (TDL) on Monday, July
10, and a separate tour on Tuesday, July 11. While the TDL tour was great fun for all theplayers, it was also a day to experience the time difference, exam fatigue, and humidity of theJapanese summer, as the area around Tokyo began to record extremely hot days (with hightemperatures of 35o C or higher) on that day, July 10. Visits to the Kashiwa Campus of the
University of Tokyo, Meiji Yasuda Life Insurance Company, JAMSTEC Yokohama ResearchLaboratory, Mitsubishi Electric Event Square (METoA Ginza), NTT Musashino Researchand Development Organization, Karakuri Corporation, Tokyo University of Science MathExperience Hall, Meiji Jingu Shrine, Harajuku, Ueno Park, and the Tokyo Metropolitan
Museum of Modern Art. Harajuku, Ueno Park/Akihabara, and Kanda University of Foreign
Studies Sports were also arranged. Each participant applied for the tour by smartphone at theregistration desk. The tour of Japan's leading research institutes and companies must havestimulated the intellectual curiosity of the athletes from each country. We would like toexpress our sincere gratitude to all those who cooperated in this endeavor.

Farewell Party
The Farewell Party was held on July 12 (Wed.) at Tokyo Bay Makuhari Hall after the closing
ceremony (18:00 - 20:00). The party was a standing buffet style party where the athletes fromeach country interacted with each other, and the venue was filled with young energy andunited by the live background music by KUREAGE, a five-sense concerto, and the Bon dance“Sosu Odori (prime number dance)” performed in collaboration with Nora Bon Odori no Kai
as an attraction. For the athletes, it was a memorable moment to decorate their last evening
in Japan.

48

5Comments (After the IMO2023 Chiba, JAPAN)

After the conference, the heads of delegations and executives of each country sent numerous
thank-you notes and positive, constructive comments and opinions about the conference tothe Executive Committee. Some of them are listed below.
The hotel (scenery) and food were excellent.
The hotel (view) and food were excellent.
I was looking forward to visiting Japan.
I enjoyed the excursion and the choice of courses.
I would have liked to have eaten more Japanese food.
The hotel rooms were small but clean.
I would have liked to explore the city a little more.
The players only walked around the area around their lodgings (hotel) except during theexcursion, and some said they would have liked to walk around the local town a little more.
However, they rated the view of Chiba from the hotel as “excellent.

6

Balance Sheet

IncomeSpending

Item

Amount（円）current year donation

45,430,040

past year donation

105,381,000

JST support

179,546,760

entry fee

Abstract

Item

Amount（円）Abstract

2,374,805

T-shirt、Medal and so on

18,870,793

secretariat stuff salaryhonorarium

16,991,498

volunteers、oﬃcials honorarium

40,038,272

travel expenses

93,288,584

hotel fee(日航成田・APA）

Foundation contribution

12,225,176

outsourcing cost

114,292,770

secretariat、ceremony、excursion

Total income

382,621,248

printing cost

3,363,898

venue rental fee

33,076,819

幕張Messe、幕張hole、TKP holeconference fee

67,395,105

Hotel日航成田、APA hotel

consumables
Foundation deposit personnel costs

communication expenses

515,333

insurance fee

157,132

miscellaneous expensses

106,692

transfer fee

343,738

past year spending

31,844,081

Total expenditure382,621,248

49

Ⅹ Photo Gallery【Haneda Airport Arrival】【Signboard】【Bus transfer】【Opening ceremony venue】

50

【Jury Meeting】【Keiko Nagaoka Minister of Education】【Tsuyoshi Soeda Chairman of Organizing Commissioner】【Keisuke Koide Contestant oath】【 IMO Board Prof. Gregor Dolinar】【Opening ceremony Japan team】【Contest hall】

51

【Ganbaruzo～ Japan team】【After Contest】【Team meeting after contest】【Chakai】【 Jane Street Hub】

【Furoshiki workshop】【HUAWEI Booth】【Japanese company Booth】

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【Corporate hub】

【Compatible with Japanese company】【Discussion after the contest】【Tokyo Disneyland】

53

【Lecture of Prof. Akiyama】【Tokyo University of Science
The Mathematical
Experience hall】【Japan Agency for Marine-Earth Science and Technology】

54

【Koukyo (Imperial Palace)】【Kavli Institute for the Physics and Mathematics of the Universe】【Sports Event】

55

【Before Closing ceremony】【Shyunichi Kamiya mayor of Chiba City】【 IMO Board Prof. Gregor Dolinar】【Medal Award】【Mirzakhani Awards】

56

【The Mathematical Olympiad Flag from Japan to the United Kingdom】【Takahiko Fujita Exective Committee Chairman】 【Farewell party】【Japanese team after the closing ceremony】 【Ministry of Education Courtesy Call】

57

Ⅺ Sponsors スポンサー

国際数学オリンピック日本大会
IMO2023 スポンサー
以下は、公益財団法人数学オリンピック財団を通じてご支援をいただいたスポンサーとパート
ナーです。
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プラチナパートナー
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学校法人 駿河台学園

公益財団法人 豊田理化学研究所

一般財団法人 数理科学振興会

一般社団法人 東京倶楽部

公益財団法人 孫正義育英財団

公益社団法人 日本アクチュアリー会

公益財団法人 日本数学検定協会

学校法人 河合塾

65

58

〇IMOF シルバースポンサー
IMOF シルバースポンサー

IMOF プラチナスポンサー
HUAWEI〇IMOF
シルバースポンサー
QuantCo
愛尖子

Jane Street

共催

国立研究開発法人 科学技術振興機構(JST)

後

援

文部科学省
一般社団法人 日本数学会
公益社団法人 日本数学教育学会
公益財団法人 ちば国際コンベンションビューロー

協力団体
神田外語大学
国際基督教大学
早稲田大学
東京理科大学株式会社 steAm
ポケトーク株式会社

5966

国立国会図書館デジタルコレクションⒸ国立天文台1 day Answer Sheets folder (front)

国立国会図書館デジタルコレクション

1 day Answer Sheets folder (back)
67Ⓒ国立天文台第64回 国際数学オリンピック(IMO2023)日本大会 報告書
2024 年 3 月 31 日発行

発行所

公益財団法人 数学オリンピック財団〒160-0022 東京都新宿区新宿 7-26-37-2D
TEL：03-5272-9790 FAX：03-5272-9791
HP：https://www.imojp.org/

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