Problem:


Score : 200 points

Problem Statement

There are four towns, numbered 1,2,3 and 4.
Also, there are three roads. The i-th road connects different towns a_i and b_i bidirectionally.
No two roads connect the same pair of towns. Other than these roads, there is no way to travel between these towns, but any town can be reached from any other town using these roads.

Determine if we can visit all the towns by traversing each of the roads exactly once.

Constraints

1 \leq a_i,b_i \leq 4(1\leq i\leq 3)

a_i and b_i are different. (1\leq i\leq 3)

No two roads connect the same pair of towns.

Any town can be reached from any other town using the roads.

Input

Input is given from Standard Input in the following format:

a_1 b_1
a_2 b_2
a_3 b_3

Output

If we can visit all the towns by traversing each of the roads exactly once, print YES; otherwise, print NO.

Sample Input 1

4 2
1 3
2 3

Sample Output 1

YES

We can visit all the towns in the order 1,3,2,4.

Sample Input 2

3 2
2 4
1 2

Sample Output 2

NO

Sample Input 3

2 1
3 2
4 3

Sample Output 3

YES



Sample input:
4 2
1 3
2 3


Sample output:
YES

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-
# スペース区切りの整数の入力
def walk(a,b,c):
    a.extend(b)
    a.extend(c)
    #print(a)
    count1=a.count(1)
    count2=a.count(2)
    count3=a.count(3)
    count4=a.count(4)
    list=[count1,count2,count3,count4]
    #print(list)
    if list.count(1)==2 and list.count(2)==2:
        return print("YES")
    else:
        return print("NO")
a = list(map(int, input().split()))
b = list(map(int, input().split()))
c = list(map(int, input().split()))
walk(a,b,c)

Submission status: Accepted

Solution code:
# 入力 a1-3, b1-3
a = []
b = []
for i in range(3):
    a0, b0 = [int(i) for i in input().split()]
    if a0 != b0:
        a.append(a0)
        b.append(b0)
    else:
        print("NO")

# 制約条件
if 1 <= all(a + b) <= 4:
    if a[0] + b[0] != a[1] + b[1] and a[1] + b[1] != a[2] + b[2] and a[2] + b[2] != a[0] + b[0]:
        one = (a + b).count(1)
        two = (a + b).count(2)
        three = (a + b).count(3)
        four = (a + b).count(4)
        if 1 <= one <=2 and 1 <= two <=2 and 1 <= three <=2 and 1 <= four <=2:
            print("YES")
        else:
            print("NO")
    else:
        print("NO")
else:
    print("NO")

Submission status: Accepted

Solution code:
import collections

a1,b1=map(int,input().split())
a2,b2=map(int,input().split())
a3,b3=map(int,input().split())
lst=sorted([a1,b1,a2,b2,a3,b3])
ans=[]
l=collections.Counter(lst).values()
for i in l:
    ans.append(i)
print('YES') if ans==[1,2,2,1] else print('NO')

Submission status: Accepted

Solution code:
a1, b1 = [int(i) for i in input().split()]
a2, b2 = [int(i) for i in input().split()]
a3, b3 = [int(i) for i in input().split()]


d = [[a1, b1], [a2, b2], [a3, b3]]
dl = [a1, b1, a2, b2, a3, b3]


def findn(n,l):
    res = []
    resl = []
    for it, t in enumerate(l):
        for iv, v in enumerate(t):
            if n == v:
                if iv == 0:
                    res.append(t[1])
                else:
                    res.append(t[0])
                lc = l[:]
                del lc[it]
                resl.append(lc)
    return res, resl



for i in range(1, 5):
    s, rest = findn(i, d)
    for iv, v in enumerate(s):
        last, lrest = findn(v, rest[iv])
        for ia, a in enumerate(last):
            res, nul = findn(a, lrest[ia])
            if len(res) >0 :
                judge = "YES"
            else:
                judge = "NO"

for i in range(1, 5):
    if not(i in dl):
        judge = "NO"

print(judge)

Submission status: Accepted

Solution code:
print("YES") if sum([sum(list(map(int,input().split()))) for i in range(3)]) == 15 else print("NO")

Submission status: Accepted

Solution code:
inputList = []
inputList.extend(int(i) for i in input().split())
inputList.extend(int(i) for i in input().split())
inputList.extend(int(i) for i in input().split())

one = 0
two = 0
three = 0
four = 0

for i in inputList:
    if i == 1:
        one = one + 1
    elif i == 2:
        two = two + 1
    elif i == 3:
        three = three + 1
    elif i == 4:
        four = four + 1

if one < 1 or one >= 3 or two < 1 or  two >= 3 or three < 1 or three >= 3 or four < 1 or four >= 3:
    print('NO')
else:
    print('YES')

Submission status: Accepted

Solution code:
in_a = input().split(" ")
in_b = input().split(" ")
in_c = input().split(" ")

total_a = set(in_a + in_b)
total_b = set(in_b + in_c)
total_c = set(in_c + in_a)


if len(total_a) != 4 and len(total_b) != 4 and len(total_c) != 4:
    print("NO")
else:
    print("YES")

Submission status: Accepted

Solution code:
a = []
for i in range(3):
  s,t = map(int, input().split())
  a.append(s)
  a.append(t)
b = [a.count(i)%2 for i in a]
if 0 not in a and b.count(1) == 2 or b.count(1) == 0:
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
k1,k2 = [int(x) for x in input().split(' ')]
k3,k4 = [int(x) for x in input().split(' ')]
k5,k6 = [int(x) for x in input().split(' ')]
K = [k1,k2,k3,k4,k5,k6]
ss = [0,0,0,0]
for k in K:
    ss[k-1] += 1

ans = 'YES'
for s in ss:
    if s == 0:
        ans = 'NO'
    if s >= 3:
        ans = 'NO'
print(ans)

Submission status: Accepted

Solution code:
import collections

list_for_node_count = []

for _ in range(3):
    list_for_node_count.extend(input().split())
    
result_of_node_count = collections.Counter(list_for_node_count)

num_of_node = len(result_of_node_count)
odd_node_count = 0

for x in result_of_node_count.values():
    if int(x)%2 == 1:
        odd_node_count += 1

if odd_node_count == 2 or odd_node_count == 0:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
#coding:utf-8

a0,b0= map(int,input().split())
a1,b1 = map(int,input().split())
a2,b2 = map(int,input().split())

a=[a0,a1,a2,b0,b1,b2]

if a.count(1) > 2:
	print('NO')
elif a.count(2) > 2:
	print('NO')
elif a.count(3) > 2:
	print('NO')
elif  a.count(4) >2:
  print('NO')
else:
	print('YES')

Submission status: Accepted

Solution code:
L = [list(map(int,input().split())) for i in range(3)]

a = []

ans = "YES"
for i in range(3):
    a.append(L[i][0])
    a.append(L[i][1])

for i in range(1,5):
    if a.count(i) >= 3:
        ans = "NO"

print(ans)

Submission status: Accepted

Solution code:
ab1 = list(map(int, input().split()))
ab2 = list(map(int, input().split()))
ab3 = list(map(int, input().split()))
roots = [ab1,ab2,ab3]
rootContainCity = []
rootContainCity.extend(ab1)
rootContainCity.extend(ab2)
rootContainCity.extend(ab3)

viaCityList = []
startOrGoalCityList = []

for i in range(4):
    if rootContainCity.count(i+1) == 2:
        viaCityList.append(i+1)
    else:
        startOrGoalCityList.append(i+1)
if len(viaCityList) == 2 and len(startOrGoalCityList) == 2:
    if [viaCityList[0],viaCityList[1]] in roots or [viaCityList[1],viaCityList[0]] in roots:
        print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a1, b1 = map(int, input().split())
a2, b2 = map(int, input().split())
a3, b3 = map(int, input().split())

li = [a1, b1, a2, b2, a3, b3]

s = 0
t = 0
for i in range(len(li)):
    if li[i] == 2:
        s += 1
    if li[i] == 3:
        t += 1
if s == 2 and t == 2:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
import copy
roads = []
roads2 = []
roads_stay = []
for s in range(3):
    a = [int(i) for i in input().split()]
    roads += [a]
lines=[]
for i in roads:
    lines.append(i[0])
    lines.append(i[1])
#print(lines)
copys=copy.deepcopy(lines)
for i in range(len(lines)):
    lines=copy.deepcopy(copys)
    form=True if i%2==0 else False
    #print(lines)
    #print('form {} i={}'.format(form,i))
    if form:
        tag=lines[i+1]
        end=[lines[i],lines[i+1]]
        lines[i]=0
        lines[i+1]=0
    else:
        tag=lines[i-1]
        end=[lines[i-1],lines[i]]
        lines[i]=0
        lines[i-1]=0
    flag=True

    while sum(lines)!=0:
        #print('us')
        if tag in lines:
            index=lines.index(tag)
            form = True if index % 2==0 else False
            if form:
                tag = lines[index + 1]
                end += [lines[index + 1]]
                lines[index] = 0
                lines[index + 1] = 0
            else:
                tag = lines[index - 1]
                end += [lines[index - 1]]
                lines[index] = 0
                lines[index - 1] = 0
        else:
            break
    if len(set(end))==4 and sum(lines)==0:
        print('YES')
        exit(0)
    #print('next')

print('NO')

Submission status: Accepted

Solution code:
ab = [[], [], [], [], []]
for i in range(3):
    a, b = map(int, input().split())
    ab[a].append(b)
    ab[b].append(a)

ways = [False] * 4


def f(now, count):
    if count > 4:
        return False
    for n in ab[now]:
        if ways[n - 1]:
            continue
        ways[n - 1] = True
        if all(ways):
            print("YES")
            exit()
        f(n, count + 1)
        ways[n - 1] = False

for i in range(1, 5):
    ways = [False] * 4
    ways[i - 1] = True
    f(i, 1)
    ways[i - 1] = False
print("NO")

Submission status: Accepted

Solution code:
a = [int(i) for i in input().split()] 
b = [int(i) for i in input().split()] 
c = [int(i) for i in input().split()] 

a.sort()
b.sort()
c.sort()

X = []

X.append(a[0])
X.append(a[1])
X.append(b[0])
X.append(b[1])
X.append(c[0])
X.append(c[1])

X.sort()
Y = set(X)
Z = set([1,2,3,4])
if Y != Z:
    print("NO")

w = [i for i in set(X) if X.count(i) > 1]

if w == a:
    print("YES")
elif w == b:
    print("YES")
elif w == c:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
# coding: utf-8
# Your code here!
num =[]
ans =0
for i in range(3):
    x,y = map(int,input().split(" "))
    num.append(x)
    num.append(y)
for i in range(1,5):

    if num.count(i)==3:
        ans +=1
if ans>0:
    print("NO")
else:
    print("YES")

Submission status: Accepted

Solution code:
def main():
	bridge = [0 for i in range(4)]
	for i in range(3):
		a, b = map(int, input().split())
		bridge[a - 1] += 1
		bridge[b - 1] += 1
	m = max(bridge)
	if m == 3:
		print("NO")
	else:
		print("YES")

if __name__ == '__main__':
	main()

Submission status: Accepted

Solution code:
a1, b1 = (int(i) for i in raw_input().split(' '))
a2, b2 = (int(i) for i in raw_input().split(' '))
a3, b3 = (int(i) for i in raw_input().split(' '))


def func():
    count_1 = 0
    count_2 = 0
    count_3 = 0
    count_4 = 0
    for x in [a1,a2,a3,b1,b2,b3]:
        if x == 1:
            count_1 += 1
        elif x == 2:
            count_2 += 1
        elif x ==3:
            count_3 += 1
        elif x ==4:
            count_4 += 1
        else:
            print('error')

    for count in [count_1, count_2,count_3,count_4]:
        if count == 0 or count >= 3:
            print('NO')
            return
    print('YES')

func()

Submission status: Accepted

Solution code:
lis = [1,2,2,3,3,4]
li = []
for i in range(3):
    a,b, = map(int,input().split())
    li.append(a)
    li.append(b)
li.sort()
if li == lis:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
p=0
z= [0,0,0,0,0]
a,b=input().split( )
c,d=input().split( )
e,f=input().split( )
x = [a,b,c,d,e,f]
for i in range(6):
  x[i]=int(x[i])
  z[x[i]]=z[x[i]]+1
for i in range(1,5):
  if z[i] == 3:
    p = 1
if p==1:
  print ("NO")
else:
  print("YES")

Submission status: Accepted

Solution code:
from collections import  Counter
a,b = map(int,input().split())
c,d = map(int,input().split())
e,f = map(int,input().split())

a = [a,b,c,d,e,f]
al = list(Counter(a))

if a.count(1)>2 or a.count(2)>2 or a.count(3)>2 or a.count(4)>2:
    print('NO')
else:
    print('YES')

Submission status: Accepted

Solution code:
l = list()
flg=True
for i in range(3):
  l.extend(input().split())
cnt = [0,0,0,0]
l = [int(i) for i in l]
for i in l:
  cnt[i-1]+=1
for i in cnt:
  if i > 2:
    flg=False
if flg:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
cnt = [0] * 5
for _ in range(3):
    s, t = map(int, input().split())
    cnt[s] += 1
    cnt[t] += 1
if cnt.count(2) == 2 and cnt.count(1) == 2:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
nums = [input().split() for i in range(3)]
numss = nums[0] + nums[1] + nums[2]
if numss.count('1') >= 3 or numss.count('2') >= 3 or numss.count('3') >= 3 or numss.count('4') >= 3: 
    print("NO")
else:
    print("YES")

Submission status: Accepted

Solution code:
a=[0,0,0,0,0,0]
a[0],a[1] = map(int,input().split())
a[2],a[3] = map(int,input().split())
a[4],a[5] = map(int,input().split())

n1=a.count(1)
n2=a.count(2)
n3=a.count(3)
n4=a.count(4)

if n1<3:
    if n1>0:
        if n2<3:
            if n2>0:
                if n3<3:
                    if n3>0:
                        if n4<3:
                            if n4>0:
                                print("YES")
                                exit()
print("NO")

Submission status: Accepted

Solution code:
def main():
    edges = dict()

    for _ in range(3):
        a, b = map(int, input().split())
        edges[a] = edges.get(a, 0) + 1
        edges[b] = edges.get(b, 0) + 1

    odds = 0
    for i, cnt in edges.items():
        if cnt % 2 == 1:
            odds += 1

    if odds <= 2:
        print('YES')
    else:
        print('NO')

main()

Submission status: Accepted

Solution code:
listA=[] #appendのために宣言が必要
while True:
    try:
        listA.append(list(map(int,input().split())))

    except:
        break;
        #または、quit(),os.exit()をして止める。

#print(listA)
listB=[]
for i in range(len(listA)):
    listB.extend(listA[i])
#print(listB)
listc=[]
listc=[listB.count(i) for i in range(1,5)]
#print(listc)
count1=listc.count(1)
#print(count1)
if min(listc) > 0 and sum(listc)>5 and count1 <3:
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
import sys
a=sys.stdin.read().split()
print(["YES","NO"][bool(sum(True for b in set(a)if a.count(b)>2))])

Submission status: Accepted

Solution code:
import sys
# A,B = [int(n) for n in input().split()]
# N = int(input())
A = [0]*3
ptr = [[0,1,2],[0,2,1],[1,2,0],[1,0,2] ,[2,1,0], [2,0,1]]
for i in range(3):
    A[i] = [int(n) for n in input().split()]


for l in ptr:
    tmp = A[l[0]][0]
    ok = True
    for i in l:
        if not (tmp in A[i]):
            ok = False
            break
        elif(tmp == A[i][0]):
            tmp = A[i][1]
        else:
            tmp = A[i][0]
    if(ok):
        print("YES")
        sys.exit()
    tmp = A[l[0]][1]
    ok = True
    for i in l:
        if not (tmp in A[i]):
            ok = False
            break
        elif(tmp == A[i][0]):
            tmp = A[i][1]
        else:
            tmp = A[i][0]
    if(ok):
        print("YES")
        sys.exit()
print("NO")

Submission status: Accepted

Solution code:
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sat Feb  9 20:41:09 2019

@author: shinjisu
"""


# 2019/2/9 Yahoo
def getInt(): return int(input())


def getIntList(): return [int(x) for x in input().split()]


def getIntLines(n): return [int(input()) for i in range(n)]


def zeros(n): return [0]*n


def db(x):
    global debug
    if debug:
        print(x)


def probA():
    N, K = getIntList()
    db((N, K))
    if (N+1)//2>=K:
        print('YES')
    else:
        print('NO')


def probB():
    a, b = zeros(3), zeros(3)
    db((a,b))
    for i in range(3):
        a[i], b[i] = getIntList()
    db((a,b))
    c = set([])
    e = zeros(5)
    for i in range(3):
        c.add(a[i])
        c.add(b[i])
        e[a[i]] += 1
        e[b[i]] += 1
    db((c,e))
    c0,c1,c2,c3,c4=0,0,0,0,0
    for i in range(1, 5):
        if e[i]==0:
            c0 += 1
        elif e[i] == 1:
            c1 += 1
        elif e[i] == 2:
            c2 += 1
        elif e[i] == 3:
            c3 += 1
        else:
            c4 += 1
    db((c0,c1,c2,c3,c4))
    if c1 == 2 and c2 == 2: 
        print('YES')
    else:
        print('NO')


def probC():
    return 0


debug = False
probB()

Submission status: Accepted

Solution code:
P1 = [int(x) for x in input().split()]
P2 = [int(x) for x in input().split()]
P3 = [int(x) for x in input().split()]
P = [0] * 4
count = 0
for i in range(0,2):
    P[P1[i]-1] += 1
    P[P2[i]-1] += 1
    P[P3[i]-1] += 1
for i in range(0,4):
    if P[i] == 3:
        count = 1
if count == 0:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a = []
for i in range(3):
    a.append(map(int, raw_input().split()))

b = []
for i in range(3):
	for j in range(2):
		b.append(a[i][j])

if b.count(1) <= 2 and b.count(2) <= 2 and b.count(3) <= 2 and b.count(4) <= 2:
	print("YES")

else:
	print("NO")

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-
import sys
# ----------------------------------------------------------------
# Use Solve Function

def solve(lines):
    counts = [0,0,0,0]
    for i in range(3):
        a,b = map(int, lines.pop(0).split(' '))
        counts[a-1] += 1
        counts[b-1] += 1

    if max(counts) == 2 and min(counts) == 1:
        print('YES')
    else:
        print('NO')
#
# main
#
lines = [x.strip() for x in sys.stdin.readlines()]

#
# solve !!
#
solve(lines)

Submission status: Accepted

Solution code:
ab1 = input().split(" ")
ab2 = input().split(" ")
ab3 = input().split(" ")
line = []
count = []

for i in range(2):
    line.append(int(ab1[i]))
    line.append(int(ab2[i]))
    line.append(int(ab3[i]))

count.append(line.count(1))
count.append(line.count(2))
count.append(line.count(3))
count.append(line.count(4))

if(count.count(1) == 2 and count.count(2) == 2):
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
# coding:utf-8

machi = dict()
for i in range(4):
    machi[i+1] = []

for _ in range(3):
    a, b = map(int, input().split())
    machi[a].append(b)
    machi[b].append(a)

# 始点と終点を決める
count = 0
start, end = 0, 0
for i in range(4):
    if len(machi[i+1]) == 1:
        if count == 0:
            start = i+1
            count += 1
        else:
            end = i+1

# 探索開始
if (start != 0) & (end != 0):
    second = machi[start][0]
    third = machi[end][0]
    if third in machi[second]:
        print("YES")
    else:
        print("NO")
else:
    print("NO")

Submission status: Accepted

Solution code:
# coding: utf-8

cnt=[0,0,0,0]
flg=True

for i in range(3):
    a,b=map(int,input().split())
    cnt[a-1]+=1
    cnt[b-1]+=1

for i in range(4):
    if cnt[i]==3:
        flg=False

if flg:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
line_list = []

for i in range(3):
    a, b = map(int, input().split())
    line_list.append([a, b])
    line_list.append([b, a])

ans = 'YES'

for now_point in [1, 2, 3, 4]:
    count = 0
    for i in range(len(line_list)):
        if line_list[i][0] == now_point:
            count += 1
    if count == 3:
        ans = 'NO'
        break

print(ans)

Submission status: Accepted

Solution code:
l1 = list(map(int, input().split()))
l2 = list(map(int, input().split()))
l3 = list(map(int, input().split()))

total = [1]
now = 1
l = [l1,l2,l3]

for i in range(3):
    for ll in l:
        if now in ll:
            ll.pop(ll.index(now))
            now = max(ll)
            total.append(now)
            l.pop(l.index(ll))

if 1 in total and 2 in total and 3 in total and 4 in total:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
from collections import Counter
A = []
for i in range(3):
    a, b = map(int, input().split())
    A.append(a)
    A.append(b)
A = sorted(Counter(A).most_common())
ans = 'NO'
if A == [(1, 1), (2, 2), (3, 2), (4, 1)]:
    ans = 'YES'
print(ans)

Submission status: Accepted

Solution code:
a = []
b = []
c = []
li = []
li2 = []
for i in range (3):
    if i == 0:
        a = list(map(int, input().split(' ')))
    if i == 1:
        b = list(map(int, input().split(' ')))
    if i == 2:
        c = list(map(int, input().split(' ')))
li = a
li.extend(b)
li.extend(c)
li = sorted(li)
for s in range (4):
    li2.append(li.count(s+1))

li2 = sorted(li2)
if li2 == [1, 1, 2, 2]:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
n1=0
n2=0
n3=0
n4=0

for i in range(3):
 nData = []
 nData  = input().rstrip().split(' ')

 nN1 = int(nData[0])
 nN2 = int(nData[1])

 if nN1==1:
  n1+=1
 elif nN1==2:
  n2+=1
 elif nN1==3:
  n3+=1
 elif nN1==4:
  n4+=1

 if nN2==1:
  n1+=1
 elif nN2==2:
  n2+=1
 elif nN2==3:
  n3+=1
 elif nN2==4:
  n4+=1

if n1==3:
 print('NO')
elif n2==3:
 print('NO')
elif n3==3:
 print('NO')
elif n4==3:
 print('NO')
else:
 print('YES')

Submission status: Accepted

Solution code:
# coding: utf-8
count = {x+1: 0 for x in range(4)}
for _ in range(3):
    a, b = list(map(int, input().split()))
    count[a] += 1
    count[b] += 1
if 3 in count.values():
    print('NO')
else:
    print('YES')

Submission status: Accepted

Solution code:
abs = []
for i in range(3):
  a, b = map(int, input().split())
  abs.append(a)
  abs.append(b)

ok = True
for i in [1,2,3,4]:
  icnt = abs.count(i)
  if icnt == 0 or icnt > 2:
    ok = False

if ok:
  print('YES')
else:
  print('NO')

Submission status: Accepted

Solution code:
import sys, copy, math, collections, itertools

a1,b1=map(int,input().split())
a2,b2=map(int,input().split())
a3,b3=map(int,input().split())
l=[]
l+=[a1,a2,a3,b1,b2,b3]
d=[0,0,0,0]
for i in l:
    d[i-1]+=1

# 偶数次数
a=len([i for i in d if i%2==0])
if a == 2:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-

n = 3
e = [[int(i) for i in input().split()] for i in range(n)]

for path in e:
    if 1 in path:
        path.sort()
        next_city = path[1]

        e.remove(path)
        break



for path in e:
    if next_city in path:
        if next_city == path[0]:
            next_city = path[1]
        else:
            next_city = path[0]

        e.remove(path)
        break


for path in e:
    if next_city in path:
        if next_city == path[0]:
            next_city = path[1]
        else:
            next_city = path[0]
        e.remove(path)
        break


if len(e) == 0:
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
# -*- coding: utf-8 -*-
lst = []


x,i = map(int, input().split())
lst.append(x)
lst.append(i)
y,j = map(int, input().split())
lst.append(y)
lst.append(j)
z,j = map(int, input().split())
lst.append(z)
lst.append(j)


a = (lst.count(1))
b = (lst.count(2))
c = (lst.count(3))
d = (lst.count(4))

if a <3 and b <3 and c <3 and d <3 :
    print('YES')
else:
    print('NO')

Submission status: Accepted

Solution code:
ls = []
for i in range(3):
  a,b = list(map(int, input().split()))
  ls.append(a)
  ls.append(b)
#print(ls)

c1 = ls.count(1)
c2 = ls.count(2)
c3 = ls.count(3)
c4 = ls.count(4)
lst = [c1,c2,c3,c4]

if lst.count(2) == 2 and lst.count(1) == 2:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
def main() -> None:
    r = (str(input()) + " " + str(input()) + " " +  str(input())).split()
    pos = {
        1: 0,
        2: 0,
        3: 0,
        4: 0,
    }
    for i in r:
        pos[int(i)] += 1

    num = 0
    for i in pos.values():
        if i >= 2:
            num = num + 1

    print("%s" % "YES" if num >= 2 else "NO")


if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
check = [0] * 4
for i in range(3):
    a, b = map(int,input().split())
    check[a-1]+=1
    check[b-1]+=1
check.sort()
if check == [1,1,2,2]:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
arr1=list(map(int,input().split()))
arr2=list(map(int,input().split()))
arr3=list(map(int,input().split()))
arrall=arr1+arr2+arr3
num=[]
for i in range(4):
    num.append(arrall.count(i+1))
num.sort()
if num == [1,1,2,2] :
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
p = []
for i in range(3):
    a = input().rstrip().split(" ")
    p.append(int(a[0]))
    p.append(int(a[1]))
#print(p)

c = []
for i in range(4):
    a = p.count(i + 1)
    c.append(a)
c.sort()

if c == [1, 1, 2, 2]:
    print("YES")
else:
    print("NO")

Submission status: Accepted

Solution code:
a1, b1 = map(int, input().split())
a2, b2 = map(int, input().split())
a3, b3 = map(int, input().split())

all_num = []
all_num.append(a1)
all_num.append(a2)
all_num.append(a3)
all_num.append(b1)
all_num.append(b2)
all_num.append(b3)

for x in range(1, 5):
    if all_num.count(x) >= 3:
        print('NO')
        break
else:
    print('YES')

Submission status: Accepted

Solution code:
import copy

def function(nums):
	path = copy.deepcopy(nums)
	clear = []

	newpath = 0
	for p1 in nums:
		for p2 in nums:
			if p1[0] == p2[1] and p1 != p2 :
				newpath = [[p1[1], p2[0]]]
				clear.append(p1[0])
				path.remove(p1)
				path.remove(p2)
				break
			elif p1[1] == p2[0] and p1 != p2 :
				newpath = [[p1[0], p2[1]]]
				clear.append(p1[1])
				path.remove(p1)
				path.remove(p2)
				break
			elif p1[1] == p2[1] and p1 != p2 :
				newpath = [[p1[0], p2[0]]]
				clear.append(p1[1])
				path.remove(p1)
				path.remove(p2)
				break
			elif p1[0] == p2[0] and p1 != p2 :
				newpath = [[p1[1], p2[1]]]
				clear.append(p1[0])
				path.remove(p1)
				path.remove(p2)
				break
		if len(clear) > 0:
			break
	newpath.append(path[0])

	if (newpath[0][0] == newpath[1][0] or newpath[0][0] == newpath[1][1] or newpath[0][1] == newpath[1][0] or newpath[0][1] == newpath[1][1]) and newpath[0] != newpath[1]:
		clear.append(newpath[0][0])
		clear.append(newpath[0][1])
		clear.append(newpath[1][0])
		clear.append(newpath[1][1])
		clear = list(set(clear))
	
	if 1 in clear and 2 in clear and 3 in clear and 4 in clear:
		print('YES')
	else:
		print('NO')

def main():
	strs = [input() for i in range(3)]
	nums = [[int(_.split(' ')[0]),int(_.split(' ')[1])] for _ in strs]
	function(nums)

if __name__ == '__main__':
	main()

Submission status: Accepted

Solution code:
#coding:utf-8
import collections

a = []
b = []
for i in range(3):
    temp = list(map(int, input().split()))
    a.append(temp[0]-1)
    b.append(temp[1]-1)

c = []
for i in range(3):
    c.append([a[i], b[i]])
    c.append([b[i], a[i]])
    
def hitohude(route):
    if not (0 in route and 1 in route and 2 in route and 3 in route):
        return False
        
    for i in range(3):
        if [route[i], route[i+1]] in c:
            continue
        else:
            return False
    return True

finish=False
for i in range(4):
    for j in range(4):
        for k in range(4):
            for l in range(4):
                route = [i,j,k,l]
                flag = hitohude(route)
                if flag == True:
                    print('YES')
                    finish = True
                if finish==True:
                    break
            if finish==True:
                break
        if finish==True:
            break
    if finish==True:
        break
if finish==False:
    print('NO')

Submission status: Accepted

Solution code:
import sys

sys.setrecursionlimit(200000)


def input():
    return sys.stdin.readline()[:-1]


def ii(t: type = int):
    return t(input())


def il(t: type = int):
    return list(map(t, input().split()))


def imi(N: int, t: type = int):
    return [ii(t) for _ in range(N)]


def iml(N: int, t: type = int):
    return [il(t) for _ in range(N)]


def solve():
    tree = [[] for _ in range(4)]
    for i in range(3):
        a, b = il()
        a -= 1
        b -= 1
        tree[a].append(b)
        tree[b].append(a)

    def dfs(prev, s, ans):
        for t in tree[s]:
            if t == prev:
                continue
            ans.append(s)
            _ = dfs(s, t, ans)
        return len(set(ans))

    return "YES" if dfs(-1, 0, []) == 3 else "NO"


if __name__ == "__main__":
    print(solve())

Submission status: Accepted

Solution code:
import itertools

lst = []
for _ in range(3):
    a, b = [int(_) for _ in input().split()]
    lst.append((a, b))

for li in itertools.permutations(lst, 3):
    for i in range(8):
        t = []
        if i & 1:
            t.append((li[0][1], li[0][0]))
        else:
            t.append(li[0])
        if i & 2:
            t.append((li[1][1], li[1][0]))
        else:
            t.append(li[1])
        if i & 4:
            t.append((li[2][1], li[2][0]))
        else:
            t.append(li[2])

        pre = t[0][1]
        for j in range(1, 3):
            if pre != t[j][0]:
                break
            pre = t[j][1]
        else:
            print("YES")
            exit()

else:
    print("NO")

Submission status: Accepted

Solution code:
a1, b1 = map(int, input().split())
a2, b2 = map(int, input().split())
a3, b3 = map(int, input().split())

block1 = 0
block2 = 0
block3 = 0
block4 = 0

pathes = [a1,a2,a3,b1,b2,b3]

for i in pathes:
    if (i == 1):
        block1 += 1
    if (i == 2):
        block2 += 1
    if (i == 3):
        block3 += 1
    if (i == 4):
        block4 += 1

if (block1 == 3 or block2 == 3 or block3 == 3 or block4 == 3):
    print("NO")
else:
    print("YES")

Submission status: Accepted

Solution code:
load = []
for i in range(3):
	tmp = input().split();
	load.append([int(tmp[0]),int(tmp[1])])
count = [0]*5
for i in range(len(load)):
	count[load[i][0]]+=1
	count[load[i][1]]+=1

ans = True

for i in range(1,5):
	if(count[i] == 3):
		ans = False

if(ans):
	print("YES")
else:
	print("NO")

Submission status: Accepted

Solution code:
"""AtCoder"""

a1, b1 = map(int, input().split())
a2, b2 = map(int, input().split())
a3, b3 = map(int, input().split())

l = [a1, b1, a2, b2, a3, b3]
sl = set(l)

if l.count(1) < 3 and l.count(2) < 3 and l.count(3) < 3 and l.count(4) < 3 and len(sl) ==4:
  print("YES")
else:
  print("NO")

Submission status: Accepted

Solution code:
a1,b1=(int(x) for x in input().split())
a2,b2=(int(x) for x in input().split())
a3,b3=(int(x) for x in input().split())

l=[a1,a2,a3,b1,b2,b3]

A=l.count(1)
B=l.count(2)
C=l.count(3)
D=l.count(4)

if A==3 or B==3 or C==3 or D==3:
  print("NO")
  
else:
  print("YES")

Submission status: Accepted

Solution code:
a1, b1=map(int, input().split())
a2, b2 = map(int, input().split())
a3, b3 = map(int, input().split())

listR = [a1, b1, a2, b2, a3, b3]
listR.sort()

flag=0
if 1 in listR and 2 in listR and  3 in listR and 4 in listR:
    listD=[]
    bef=0
    count=0
    index=0
    while index < len(listR):
        if index==0:
            bef=listR[index]
            count=1
        else:
            if listR[index]!=bef:
                if count!=1 and count!=2:
                    print("NO")
                    flag=1
                    break
                else:
                    if count==2:
                        listD.append(bef)
                    bef=listR[index]
                    count=1
            else:
                count+=1
        index+=1
    if count != 1 and count != 2 and flag==0:
        print("NO")
        flag = 1
    else:
        if count==2:
            listD.append(bef)
    if len(listD) == 2 and flag == 0:
        print("YES")
    else:
        if flag==0:
            print("NO")
else:
    print("NO")