Problem:


Score : 200 points

Problem Statement

You are given a string S consisting of lowercase English letters.
Find the lexicographically (alphabetically) smallest lowercase English letter that does not occur in S.
If every lowercase English letter occurs in S, print None instead.

Constraints

1 \leq |S| \leq 10^5 (|S| is the length of string S.)

S consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

Print the lexicographically smallest lowercase English letter that does not occur in S.
If every lowercase English letter occurs in S, print None instead.

Sample Input 1

atcoderregularcontest

Sample Output 1

b

The string atcoderregularcontest contains a, but does not contain b.

Sample Input 2

abcdefghijklmnopqrstuvwxyz

Sample Output 2

None

This string contains every lowercase English letter.

Sample Input 3

fajsonlslfepbjtsaayxbymeskptcumtwrmkkinjxnnucagfrg

Sample Output 3

d



Sample input:
atcoderregularcontest


Sample output:
b

Submission status: Wrong Answer

Solution code:
flag=1
a=input()
for i in 'abcdefghijklmnopqrstuvwxyz':
  if i in a:flag=0;break
print('None'if flag else i)

Submission status: Wrong Answer

Solution code:
s = set(list(str(input())))
s1=list(sorted(s))
for i in range(len(s1)):
    if not chr(i+97) in s1:
        print(chr(i+97))
        break
    elif chr(i+97)=='z':
        print(None)

Submission status: Wrong Answer

Solution code:
from collections import OrderedDict
s = set(list(str(input())))
s1=list(sorted(s))
t=0
if len(s1)==26:
    print(None)
for i in range(len(s1)):
    if not i+97==ord(s1[i]):
        print(chr(i+97))
        break

Submission status: Wrong Answer

Solution code:
S = input()

S = sorted(S)

S_dict = {}
cnt = 0
for s in S:
  if s not in S_dict:
    S_dict[s] = 1

print(S_dict)

ALL = 'abcdefghijklmnopqrstuvwxyz'

answer= None
for c in ALL:
  if c not in S_dict:
    answer = c
    break

print(answer)

Submission status: Wrong Answer

Solution code:
import numpy as np

s = input()
t = list("abcdefghijklmnopqrstuvwxyz")
s = list(sorted(set(s)))

ans = "None"
for i in range(min(len(s), len(t))):
    if s[i] != t[i]:
        ans = t[i]
        break

print(ans)

Submission status: Wrong Answer

Solution code:
s = input()
n = len(s)
alp = [False] * 26
for i in range(n):
    num = ord(s[i]) - ord('a')
    alp[num] = True
ok = 0
for i in range(26):
    if alp[i]:
        continue
    print(chr(ord('a') + i))
    ok = 1
if ok == 0:
    print("None")

Submission status: Wrong Answer

Solution code:
s = input()
n = len(s)
alp = [False] * 26
for i in range(n):
    num = ord(s[i]) - ord('a')
    alp[num] = True
for i in range(26):
    if alp[i]:
        continue
    print(chr(ord('a') + i))
    break

Submission status: Wrong Answer

Solution code:
#071_B
s=input()
c='a'
while c<'z':
    c=chr(ord(c)+1)
    if c not in s:
        print(c)
        exit()
print('None')

Submission status: Wrong Answer

Solution code:
s = input()
ss = sorted(set(s))
cnt = ord('a')
for c in ss:
    if ord(c) == cnt:
        cnt += 1
        print(cnt)
    else:
        print(chr(cnt))
        exit()
if cnt == ord('{'):
    print('None')
else:
    print(chr(cnt))

Submission status: Wrong Answer

Solution code:
s = input()
ss = sorted(set(s))
cnt = ord('a')
for c in ss:
    if ord(c) == cnt:
        cnt += 1
    else:
        print(chr(cnt))
        exit()
if cnt == ord('z'):
    print('None')
else:
    print(chr(cnt))

Submission status: Wrong Answer

Solution code:
s = input()
ss = sorted(set(s))
cnt = ord('a')
for c in ss:
    if ord(c) == cnt:
        cnt += 1
    else:
        print(chr(cnt))
        exit()
print('None')

Submission status: Wrong Answer

Solution code:
# coding: utf-8
S = input()
alp = "abcdefghijklmnopqrstuvwxyz"
for a in alp:
    if a not in S:
        print(a)
        exit()

Submission status: Wrong Answer

Solution code:
s=sorted(list(set(input())))
al='abcdefghijklmnopqrstuvwxyz'
for i in range(len(s)):
  if s[i]!=al[i]:
    print(al[i])
    exit()
print('None')

Submission status: Wrong Answer

Solution code:
s=sorted(list(set(input())))
al='abcdefghijklmnopqrstuvwxyz'
for i in range(len(s)):
  if s[i]!=al[i]:
    print(al[i])
    exit()

Submission status: Wrong Answer

Solution code:
s = sorted(list(set(list(input()))))
i = 0
while i < 25 and chr(i+97)==s[i]:
    i += 1
if i<=25:
    print(chr(i+97))
else:
    print("None")

Submission status: Wrong Answer

Solution code:
s = sorted(list(set(list(input()))))
i = 0
while i < 25 and chr(i+97)==s[i]:
    i += 1
if i<25:
    print(chr(i+97))
else:
    print("None")

Submission status: Wrong Answer

Solution code:
from string import ascii_lowercase


def main():
    string = input()
    count = {}
    for lcase in ascii_lowercase:
        count[lcase] = 0
    for s in string:
        count[s] += 1
    for i, count in enumerate(list(count.values())):
        if count == 0:
            print(ascii_lowercase[i])
            break
    else:
        print("None")


if __name__ == '__main__':
    main()

Submission status: Wrong Answer

Solution code:
alphabet='abcdefghijklmnopqrstuvwxyz'
S=input()
ans="non"
for a in alphabet:
    if S.count(a)==0:
        ans=a
        break
print(ans)

Submission status: Wrong Answer

Solution code:
S = list(map(str,input()))
S_new = sorted(S)
index = 0
count = 0

for i in range(0, len(S_new) - 1):
	if ord(S_new[i + 1]) - ord(S_new[i]) > 1:
		index = i
		count = 1
		break
	index = i + 1

if count == 0:
	print('None')
else:
	ans = ord(S_new[index]) + 1
	print(chr(ans))

Submission status: Wrong Answer

Solution code:
S = list(map(str,input()))
S_new = sorted(S)
index = 0

for i in range(0, len(S_new) - 1):
	if ord(S_new[i + 1]) - ord(S_new[i]) > 1:
		index = i
		break
	index = i + 1

if index == 0:
	print('None')
else:
	ans = ord(S_new[index]) + 1
	print(chr(ans))

Submission status: Wrong Answer

Solution code:
A=input()
B=sorted(set(A))

def aaa(a):
  return(ord(a))

C=list(map(aaa,B))

for i in range(26):
  if (i+97 in C)!=1:
    print(i+97)
    break
  if i==25:
    print("None")

Submission status: Wrong Answer

Solution code:
diff = set(input()) - set('abcdefghijklmnopqrstuvwxyz')
if diff:
    print(sorted(diff)[0])
else:
    print('None')

Submission status: Wrong Answer

Solution code:
S = list(map(str,input()))
S_new = sorted(S)
index = 0

for i in range(0, len(S_new) - 1):
	if ord(S_new[i + 1]) - ord(S_new[i]) > 1:
		index = i
		break

if index == 0:
	print('None')
else:
	ans = ord(S_new[index]) + 1
	print(chr(ans))

Submission status: Wrong Answer

Solution code:
S = list(map(str,input()))
S_new = sorted(S)
a = []
index = 0
print(S_new)
for i in range(0, len(S_new) - 1):
	if ord(S_new[i + 1]) - ord(S_new[i]) > 1:
		index = i
		break

if index == 0:
	print('None')
else:
	ans = ord(S_new[index]) + 1
	print(chr(ans))

Submission status: Wrong Answer

Solution code:
s=input()
master=list("abcdefghijklmnopqrstuvwxyz")
ss=sorted(set(s))
count=0
for i in master:
    if i not in ss:
        print(i)
        break
    else:
        count +=1
if count == len(s):
    print("None")

Submission status: Wrong Answer

Solution code:
r = list(set(range(97, 123)) - set(map(ord, list(input()))))
if r:
    print(chr(r[0]))
else:
    print('None')

Submission status: Wrong Answer

Solution code:
S = input()

alphabet = {
    "a": 0,
    "b": 0,
    "c": 0,
    "d": 0,
    "e": 0,
    "f": 0,
    "g": 0,
    "h": 0,
    "i": 0,
    "j": 0,
    "k": 0,
    "l": 0,
    "m": 0,
    "n": 0,
    "o": 0,
    "p": 0,
    "q": 0,
    "r": 0,
    "s": 0,
    "t": 0,
    "u": 0,
    "v": 0,
    "w": 0,
    "x": 0,
    "y": 0,
    "z": 0,
}

for i in range(len(S)):
    alphabet[S[i]] += 1

flag = True
for k, v in alphabet.items():
    if v == 0:
        print(k)
        flag = False
        break

if flag:
    print("None")

Submission status: Wrong Answer

Solution code:
import sys
input = sys.stdin.readline

def main():
    S = set(input())
    if len(S) == 26:
        print("None")
        sys.exit()
    for i in range(97, 97+26):
        if chr(i) not in S:
            print(chr(i))
            sys.exit()

if __name__ == '__main__':
    main()

Submission status: Wrong Answer

Solution code:
S = input()

judge = "abcdefghgijklmnopqrstuvwxyz"
for i in range(len(S)):
  judge = judge.lstrip(S[i])

if judge == "":
  print("None")
else:
  print(judge[0])

Submission status: Wrong Answer

Solution code:
s=input()
ans=1
all="abcdefghijklmnopqrstuvwxyz"
for i in all:
    if i not in s:
        print(i)
        ans=0
if ans==1:
    print("None")

Submission status: Wrong Answer

Solution code:
s=input()
all="abcdefghijklmnopqrstuvwxyz"
for i in all:
    if i not in s:
        print(i)
    elif i=="z":
        print("None")

Submission status: Wrong Answer

Solution code:
s = list(input())
abc = list('abcdefghijklmnopqrstuvwxyz')
abc_exist = [False] * 26

for i in range(len(s)):
  for j in range(26):
    if s[i] == abc[j]:
      abc_exist[j] = True
for k in range(26):
  if abc_exist[k] == False:
    r = abc[k]
else:
  r = 'None'
print(r)

Submission status: Wrong Answer

Solution code:
alphabet = [i for i in "abcdefghijklmnopqrstuvwxyz"]
S = input()
S_list = [i for i in S]
S_list = sorted(set(S_list),reverse=False)

ans = None

for index,i in enumerate(S_list):
    if alphabet[index] != i:
        ans = alphabet[index]
        break
print(ans)

Submission status: Wrong Answer

Solution code:
l=set(input())
allalphabet=[]
#print(l)
flag=1
for i in range(97,123,1):
    allalphabet.append(chr(i))
allalphabet=set(allalphabet)
sub=list(allalphabet-l)
#print(sub)
if len(sub)>0:
    print(sub[0])
else:
    print("None")

Submission status: Wrong Answer

Solution code:
ALPHABET = "abcdefghijklmnopqrstuvwxyz"

s = input()
for i in range(26):
    if s.count(ALPHABET[i]):
        print(ALPHABET[i])
        break
else:
    print("None")

Submission status: Wrong Answer

Solution code:
s = input()

mi = 123

for l in s:
  mi = min(ord(l), mi)
  
if mi == 123:
  print("None")
else:
  print(chr(mi))

Submission status: Wrong Answer

Solution code:
S=list(input())
import string
X= list(string.ascii_lowercase)
for i in X:
    if i not in S:
        print(i)
        break

Submission status: Wrong Answer

Solution code:
s = input()
da = 'abcdefghijklmnopqrstuvwxyz'
flag = True
for i in da:
  for j in s:
    if j == i:
      flag = False
  if not flag:
    print(i)
    break
if flag:
  print('None')

Submission status: Wrong Answer

Solution code:
s = input()
da = 'abcdefghijklmnopqrstuvwxyz'
flag = True
for i in da:
  for j in s:
    if s == i:
      flag = False
  if not flag:
    print(i)
    break
if flag:
  print('None')

Submission status: Wrong Answer

Solution code:
l=list(set(input()))
l.sort()
#print(l)
flag=1
for i in range(len(l)):
    if not(ord(l[i])==i+97):
        print(chr(i+97))
        flag=0
        break
if flag==1:
    print("None")

Submission status: Wrong Answer

Solution code:
l=sorted(list(set(input())))
#print(l)
flag=1
for i in range(len(l)):
    if not(ord(l[i])==i+97):
        print(chr(i+97))
        flag=0
        break
if flag==1:
    print("None")

Submission status: Wrong Answer

Solution code:
l=list(set(sorted(input())))
#print(l)
flag=1
for i in range(len(l)):
    if not(ord(l[i])==i+97):
        print(chr(i+97))
        flag=0
        break
if flag==1:
    print("None")

Submission status: Wrong Answer

Solution code:
ans=ord("a")
for s in sorted(input()):
    if ord(s)>ans:
        print(chr(ans))
        break
    elif ord(s)==ans:
        ans+=1
else:
    print("None")

Submission status: Wrong Answer

Solution code:
S = input()
for i in range(ord("a"), ord("z")+1):
    if chr(i) not in S:
        print(chr(i))
        break
else:
    print("No")

Submission status: Wrong Answer

Solution code:
import collections
S=sorted(str(input()))
#print(*S)
A=[]
L = collections.Counter(S)
values, counts = zip(*L.most_common())
for i in range(len(values)):
  A.append(values[i])
A.sort()

x=0
for i in range(len(A)):
  if ord(A[i])!=i+97:
    x=i+97
    break
    
print(chr(i+97) if x!=0 else "None")

Submission status: Wrong Answer

Solution code:
s = input() 

alphabet = "abcdefghijklmnopqrstuvwxyz"

delete = s and alphabet

answer = "None"
for c in alphabet:
  if c not in delete:
    answer = c
    break
print(answer)

Submission status: Wrong Answer

Solution code:
string=input()
s=set(list(string))

full=set(list("abcdefghijklmnopqrstuvwxyz"))

tmp=full-s
print(tmp)

Submission status: Wrong Answer

Solution code:
import sys
s=list(input())
s=list(set(s))
s.sort()
if len(s)==26:
    print("None")
    sys.exit()
for i in range(26):
    if i+1 >= len(s):
        print(chr(ord("a")+i))
        sys.exit()
    if chr(ord("a")+i)!=s[i]:
        print(chr(ord("a")+i))
        sys.exit()

Submission status: Wrong Answer

Solution code:
import sys
s=list(input())
s=list(set(s))
s.sort()
#print(s)
for i in range(26):
    if i+1 >= len(s):
        print(chr(ord("a")+i))
        sys.exit()
    if chr(ord("a")+i)!=s[i]:
        print(chr(ord("a")+i))
        sys.exit()
print("None")

Submission status: Wrong Answer

Solution code:
from sys import stdin, stdout

s = stdin.readline().strip('\n')
al = [True for i in range(26)]
for i in s:
  al[ord(i) - 97] = False
for i in range(97, 113):
  if al[i - 97]:
    stdout.write(str(chr(i)) + '\n')
    break
else:
  stdout.write('None\n')

Submission status: Wrong Answer

Solution code:
import string
ju = list(string.ascii_lowercase)
s = list(set(input()))
s.sort()

for i,j in zip(s,ju):
    if i!=j:
        print(j)
        exit()
print('None')

Submission status: Wrong Answer

Solution code:
sList = sorted(list(set(list(input()))))
chI = ord('a')
for i in sList:
  if chI == ord(i):
    chI += 1
  else:
    print(chr(chI))
    exit(0)

print("None")

Submission status: Wrong Answer

Solution code:
sList = sorted(list(set(list(input()))))
chI = ord('a')
for i in sList:
  if chI == ord(i):
    chI += 1
  else:
    print(chI)
    exit(0)

print("None")

Submission status: Wrong Answer

Solution code:
## 以下だめだった。
S = list(input())

# 重要：アルファベットの配列を生成
alphabets = [chr(ord('a') + i) for i in range(26)]

# 除外文字を配列に入れる
excludeS = []
for i in range(len(alphabets)):
    if alphabets[i] not in S and all(97<=ord(elem)<= 122 for elem in S):
        excludeS.append(alphabets[i])
        flag = False
    else:
        flag = True

if flag:
    print('None')
else:
    # 辞書順に並び変えて一番小さい文字を求める
    sortedExcludeS = sorted(excludeS)
    print(sortedExcludeS[0])

# ## これが正答
# S = list(input())
 
# flg = True

# #aからzに対応する
# for i in range(ord('a'), ord('z') + 1):
#     # chr(i)に対応するアルファベットの個数がS内で0だった場合の処理
#     if S.count(chr(i)) == 0:
#         flg = False
#         ans = chr(i)
#         break
 
# print("None" if flg else ans)

Submission status: Wrong Answer

Solution code:
S = list(input())

# 重要：アルファベットの配列を生成
alphabets = [chr(ord('a') + i) for i in range(26)]

# 除外文字を配列に入れる
excludeS = []
for i in range(len(alphabets)):
    if alphabets[i] not in S:
        excludeS.append(alphabets[i])
        flag = False
    else:
        flag = True

if flag:
    print('None')
else:
    # 辞書順に並び変えて一番小さい文字を求める
    sortedExcludeS = sorted(excludeS)
    minExcludeS = min(sortedExcludeS)
    print(minExcludeS)

Submission status: Wrong Answer

Solution code:
S = list(input())

# 重要：アルファベットの配列を生成
alphabets = [chr(ord('a') + i) for i in range(26)]

# 除外文字を配列に入れる
excludeS = []
for i in range(len(alphabets)):
    if alphabets[i] not in S:
        excludeS.append(alphabets[i])
        # 辞書順に並び変えて一番小さい文字を求める
        sortedExcludeS = sorted(excludeS)
        minExcludeS = min(sortedExcludeS)
        flag = False
    else:
        flag = True

if flag:
    print('None')
else:
    print(minExcludeS)

Submission status: Wrong Answer

Solution code:
S = list(input())

# 重要：アルファベットの配列を生成
alphabets = [chr(ord('a') + i) for i in range(26)]

# 除外文字を配列に入れる
excludeS = []
for i in range(len(alphabets)):
    if alphabets[i] not in S:
        excludeS.append(alphabets[i])
        # 辞書順に並び変えて一番小さい文字を求める
        sortedExcludeS = sorted(excludeS)
        minExcludeS = min(sortedExcludeS)
        flag = False
    else:
        flag = True

if flag:
    print('None')
else:
    print(minExcludeS)

Submission status: Wrong Answer

Solution code:
S = input()
l = sorted(list(set(S)))

for i in range(len(l)):
  if len(l) == 1 and S == "a":
    ans = "b"
  elif ord(l[i]) !=  97 + i:
    ans = chr(97+i)
    break
  else:
    ans = "None"

print(ans)

Submission status: Wrong Answer

Solution code:
S = input()
l = sorted(list(set(S)))

ans ="None"
for i in range(len(l)):
  if ord(l[i]) !=  97 + i:
    ans = chr(97+i)
    break

print(ans)

Submission status: Wrong Answer

Solution code:
S = input()
l = sorted(list(set(S)))

ans ="None"
number = [96]
for i in range(len(l)):
  if ord(l[i]) ==  number[-1] + 1:
    number.append(ord(l[i]))
  else:
    ans = chr(number[-1]+1)
    break

print(ans)

Submission status: Wrong Answer

Solution code:
a = input()
lst = [ord(i) for i in a]
print(chr(min(lst)))

Submission status: Wrong Answer

Solution code:
import re

S=input()

char = [chr(i) for i in range(97, 97+26)]
ans = ""

for c in char:
  result = re.match(c, S)

  if result == None:
    ans = c
    break
else:
  ans = "None"

print(ans)

Submission status: Wrong Answer

Solution code:
#071 b-not found
#A~ 65 65+26 a~97 97+26
s=input()
a=[chr(i) for i in range(97,97+26)]
for i in range(26):
    if a[i] not in s:
        ans=i
        break
print(chr(97+i))

Submission status: Wrong Answer

Solution code:
import sys


def solve(inp):
    S = inp.readline()

    alphas = {}
    for c in S:
        if c not in alphas:
            alphas[ord(c)] = 0
        alphas[ord(c)] += 1

    for c in range(ord('a'), ord('z')):
        if c not in alphas:
            return chr(c)

    return "None"


def main():
    result = solve(sys.stdin)
    if result:
        print(result)


if __name__ == '__main__':
    main()

Submission status: Wrong Answer

Solution code:
s=sorted(list(set(input())))
alph=[chr(i) for i in range(97,97+26)]
if len(s) == 26:
    print("None")
else:
    for i,j in zip(s,alph):
        if i != j:
            print(j)
            exit()

Submission status: Wrong Answer

Solution code:
s=sorted(list(set(input())))
alph=[chr(i) for i in range(97,97+26)]
for i,j in zip(s,alph):
    if i != j:
        print(j)
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
S = input()
alp = {i:0 for i in "abcdefghijklmnopqrstuvwxyz"}

for i in S:
    alp[i] += 1

ans = [i for i in alp if alp[i]==0]

if len(ans) == 0:
    print("None")
else:
    print(ans[0])

Submission status: Wrong Answer

Solution code:
s = list(input())
s.sort()
start = ord('a')

for c in s:
    if ord(c) == start:
        continue
    elif ord(c) - start == 1:
        start+=1
        continue
    else:
        print(chr(start+1))
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
S = input()

bucket = [0] * 26


def c_to_num(c):
    return ord(c) - 97


def num_to_c(num):
    return chr(num+97)


for c in S:
    bucket[c_to_num(c)] += 1

ret = 'None'
for i, n in enumerate(bucket):
    if not n:
        ret = num_to_c(i)

print(ret)

Submission status: Wrong Answer

Solution code:
li = list("abcdefghijklmnopqrstuvwxyz")
s = list(input())
cnt = [0 for i in range(26)]

for i in range(len(s)):
    for j in range(26):
        if li[j]==s[i]:
            cnt[j]+=1

for i in range(26):
    if cnt[j]==0:
        print(li[j])
        break
    elif i ==25:
        print("None")

Submission status: Wrong Answer

Solution code:
import string

s = str(input())

s_set = set(s)
alpha_set = set(string.ascii_lowercase)

res = list(alpha_set - s_set)

if len(res) == 0:
    ans = 'NONE'
else:
    ans = sorted(res)[0]

print(ans)

Submission status: Wrong Answer

Solution code:
line = input()
alpha = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]
letters = []
for i in range(len(line)):
  letters.append(line[i])
setted = sorted(set(letters))
for j in alpha[:]:
  for k in setted:
    if j == k:
      alpha.remove(j)
if len(alpha) == 0:
  print("None")
else:
  answer = alpha[0]
  print(answer)
print(setted)
print(alpha)

Submission status: Wrong Answer

Solution code:
line = input()
alpha = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]
letters = []
for i in range(len(line)):
  letters.append(line[i])
setted = sorted(set(letters))
for j in alpha:
  for k in setted:
    if j == k:
      alpha.remove(j)
answer = alpha[0]
print(answer)

Submission status: Wrong Answer

Solution code:
s = sorted(set(input()))
t = "abcdefghijklmnopqrstuvwxyz"
ans = "None"
for i in range(len(s)):
  if s[i] != t[i]:
    ans = t[i]
    break
print(ans)

Submission status: Wrong Answer

Solution code:
s = sorted(input())
characters = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','t','u','v','w','x','y','z']
ans = "None"
for i in characters:
      if i not in s:
        ans = i
        break
print(i)

Submission status: Wrong Answer

Solution code:
s = sorted(input())
characters = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','t','u','v','w','x','y','z']

for i in characters:
      if i not in s:
        print(i)
        break

Submission status: Wrong Answer

Solution code:
word = input()
al = [chr(ord("a") + i) for i in range(26)]
for i in range(len(al)):
    if not al[i] in word:
      print(al[i])
      break

Submission status: Wrong Answer

Solution code:
from sys import stdin
import bisect

s = stdin.readline().rstrip()

li = "abcdefghijklmnopqrstuvwxyz"

for i in li:
    if i not in s:
        print(i)
        exit()

Submission status: Wrong Answer

Solution code:
s=input()
a="abcdefghijklmnopqrstuvwxyz"
for i in a:
    if i in s:
        print(i)
        exit()
print('None')

Submission status: Wrong Answer

Solution code:
s = sorted(set(input()))
alp = 'abcdefghijklmnopqrstuvwxyz'

for i in alp:
    if i in s:
        pass
    else:
        print(i)
        break

Submission status: Wrong Answer

Solution code:
S = sorted(list(str(input())))
l = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']

for i in l:
  if not i in S:
    print(i)
    break

Submission status: Wrong Answer

Solution code:
s=sorted(set(input()))
l=list(range(ord("a"),ord("z")+1))
for i in range(len(s)):
    if ord(s[i]) == l[i]:
        pass
    else:
        print(chr(l[i]))
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
s=input().split()
a='abcdefghijklmnopqrstuvwxyz'
a_li=a.split()

s_set=set(s)
a_set=set(a_li)

if s_set==a_set:
    print('None')
else:
    result=list(a_set-s_set)
    result.sort()
    print(result[0])

Submission status: Wrong Answer

Solution code:
from collections import Counter,defaultdict,deque
from heapq import heappop,heappush,heapify
import sys,bisect,math,itertools
sys.setrecursionlimit(10**8)
mod = 10**9+7
def inp(): return int(sys.stdin.readline())
def inpl(): return list(map(int, sys.stdin.readline().split()))
def inpln(n): return list(int(sys.stdin.readline()) for i in range(n))

s = input()
t = 'abcdefghijklmnopqrstuvwxyz'
for i in t:
    if not i in s:
        print(i)
        break

Submission status: Wrong Answer

Solution code:
dic = {'a':False,'b':False,'c':False,'d':False,'e':False,'f':False,'g':False,'h':False,'i':False,'j':False,
       'k':False,'l':False,'m':False,'n':False,'o':False,'p':False,'q':False,'r':False,'s':False,'t':False,
       'u':False,'v':False,'w':False,'x':False,'y':False,'z':False}
s = list(input())
for i in range(len(s)):
    if dic[s[i]] == False:
        dic[s[i]]=True
for i in dic:
    if dic[i] == False:
        print(i)
        exit()
print('None')
exit()

Submission status: Wrong Answer

Solution code:
dic = {'a':False,'b':False,'c':False,'d':False,'e':False,'f':False,'g':False,'h':False,'i':False,'j':False,
       'k':False,'l':False,'m':False,'n':False,'o':False,'p':False,'q':False,'r':False,'s':False,'t':False,
       'u':False,'v':False,'w':False,'x':False,'y':False,'z':False}
s = list(input())
for i in range(len(s)):
    if dic[s[i]] == False:
        dic[s[i]]=True
for i in dic:
    if dic[i] == False:
        print(i)
        exit()
print('None')

Submission status: Wrong Answer

Solution code:
print(min(set(map(chr,range(ord("a"),ord("z"))))-set(input())or["None"]))

Submission status: Wrong Answer

Solution code:
#2019/10/22
S = open(0).readlines()
#S = input()
#print(S, type(S))
set_S=set(S)
# print(set_S)
alpha = "abcdefghijklmnopqrstuvwxyz"
# print(alpha)
productSet = sorted(set_S^set(alpha))
#print(productSet)
print("None" if len(productSet)==0 else productSet[0])

Submission status: Wrong Answer

Solution code:
#2019/10/22
S = open(0).readline()
# S = input()
# print(S)
set_S=set(S)
# print(set_S)
alpha = "abcdefghijklmnopqrstuvwxyz"
# print(alpha)
productSet = sorted(set_S^set(alpha))
#print(productSet)
print("None" if len(productSet)==0 else productSet[0])

Submission status: Wrong Answer

Solution code:
#2019/10/22
S = open(0).read()
# print(S)
set_S=set(S)
# print(set_S)
alpha = "abcdefghijklmnopqrstuvwxyz"
# print(alpha)
productSet = sorted(set_S^set(alpha))
#print(productSet)
print("None" if len(productSet)==0 else productSet[0])

Submission status: Wrong Answer

Solution code:
#2019/10/22
S = open(0).read()
#print(S)
set_S=sorted(set(S))
#print(set_S, type(set_S))
# alpha = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]
alpha = "abcdefghijklmnopqrstuvwxyz"
# print(alpha)
 
for i in range(len(alpha)):
#     print(set_S[i], alpha[i])
    if set_S[i] != alpha[i]:
        print(alpha[i])
        break

Submission status: Wrong Answer

Solution code:
#2019/10/22
S = open(0).read()
# print(S)
set_S=list(set(S))
set_S.sort()
# print(set_S)
# alpha = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]
alpha = "abcdefghijklmnopqrstuvwxyz"
# print(alpha)

for i in range(len(alpha)):
#     print(set_S[i], alpha[i])
    if set_S[i] != alpha[i]:
        print(alpha[i])
        break
    if i==len(alpha)-1:
        print("none")

Submission status: Wrong Answer

Solution code:
#2019/10/22
S = open(0).read()
# print(S)
set_S=list(set(S))
set_S.sort()
# print(set_S)
# alpha = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]
alpha = "abcdefghijklmnopqrstuvwxyz"
# print(alpha)

for i in range(len(alpha)):
    if set_S[i] != alpha[i]:
        print(alpha[i])
        break
    if i==len(alpha)-1:
        print("None")

Submission status: Wrong Answer

Solution code:
#2019/10/22
S = open(0).read()
# print(S)
set_S=list(set(S))
set_S.sort()
# print(set_S)
alpha = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]
# print(alpha)

for i in range(len(alpha)):
    if set_S[i] != alpha[i]:
        print(alpha[i])
        break
    if i==len(alpha)-1:
        print("None")

Submission status: Wrong Answer

Solution code:
#2019/10/22
S = open(0).read()
# print(S)
set_S=list(set(S))
set_S.sort()
# print(set_S)
alpha = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']
# print(alpha)

for i in range(len(alpha)):
    if set_S[i] != alpha[i]:
        print(alpha[i])
        break
    if i==len(alpha)-1:
        print("None")

Submission status: Wrong Answer

Solution code:
s=list(input())
s.sort()
char=97
num=0
while num<len(s):
    if num<len(s)-1 and s[num]==s[num+1]:
        num+=1
    else:
        if s[num]==chr(char+num):
            num+=1
        else:
            break
if num<len(s):
    print(chr(char+num))
else:
    print('None')

Submission status: Wrong Answer

Solution code:
n = list(map(str, input()))
Alpha = 'abcdefghijklmnopqrstuvwxyz'
s = list(map(str, Alpha))
ans = 'None'

for i in s:
  if i not in n:
    ans = i

print(ans)

Submission status: Wrong Answer

Solution code:
arr = [chr(i) for i in range(97, 97+26)]

s = input()

for c in arr:
    if c not in s:
        print(c)
        break

Submission status: Wrong Answer

Solution code:
s = sorted(set(input()))
r = "abcdefghijklmnopqrstuvwxyz"
for i, j in zip(s, r):
  if i != j:
    print(j)
    quit()
print("None")

Submission status: Wrong Answer

Solution code:
s=list(set((str(input()))))
s.sort()
s="".join(map(str,s))
t='abcdefghijklmnopqrstuvwxyz'
for i in range(len(s)):
    if s[i]!=t[i]:
        print(t[i])
        break
else:
    print(None)

Submission status: Wrong Answer

Solution code:
import sys
S = input()
cnt = [False] * 30
for i in S:
    if i in "abcdefghijklmnopqrstuvwxyz":
        cnt[ord(i) - ord('a')] = True
 
for i in range(len(cnt)):
    if not cnt[i]:
        print(chr(ord('a')+i))
        sys.exit()
print("None")

Submission status: Wrong Answer

Solution code:
import sys
S = input()
cnt = [False] * 30
for i in S:
    cnt[ord(i) - ord('a')] = True
 
for i in range(len(cnt)):
    if not cnt[i]:
        print(chr(ord('a')+i))
        sys.exit()
print("None")

Submission status: Wrong Answer

Solution code:
import sys
S = input()
cnt = [0] * 30
for i in range(len(S)):
    cnt[ord(S[i]) - ord('a')] += 1

for i in range(len(S)):
    if not cnt[i]:
        print(chr(ord('a')+i))
        sys.exit()
print("None")

Submission status: Wrong Answer

Solution code:
s = sorted(set(input()))
ans = "None"
for i in range(len(s)):
    if ord(s[i]) != ord("a")+i:
        ans = chr(ord(s[i])-1)
        break
print(ans)

Submission status: Wrong Answer

Solution code:
s = sorted(set(input()))
print(*s)
ans = "None"
for i in range(len(s)):
    if ord(s[i]) != ord("a")+i:
        ans = chr(ord(s[i])-1)
        break
print(ans)

Submission status: Wrong Answer

Solution code:
import string
s = input()
if string.ascii_lowercase in s:
  print("None")
else:
  for i in range(97,97+26):
    if chr(i) not in s:
      print(chr(i))
      break

Submission status: Wrong Answer

Solution code:
S=input()
s="abcdefghijklmnopqrstucwxyz"
s = list(s)
  
for si in S:
  if si in s:
  	s.remove(si)
    
if s == "":
  print("None")
else:
  print(S[0])

Submission status: Wrong Answer

Solution code:
S=input()
s="abcdefghijklmnopqrstucwxyz"
s = list(s)
  
for si in S:
  if si in s:
  	s.remove(si)
    
if S == "":
  print("None")
else:
  print(S[0])

Submission status: Wrong Answer

Solution code:
S=list(input())
A=list("abcdefghijklmnopqrstuvwxyz")
if set(S)!=set(A):
  print(A[A.index(min(S))-1])
else:
  print("None")

Submission status: Wrong Answer

Solution code:
s=input()

x=['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r',
          's','t','u','v','w','x','w','z']
          
for i in x:
    a=s.count(i) 
    if a == 0:
        print(i)
        exit()

print('None')

Submission status: Wrong Answer

Solution code:
s=list(input())
alpha=[chr(i) for i in range(97, 97+26)]
check={}
for c in alpha:
    check[c]=1
for c in s:
    check[c]-=1
for c in check:
    if check[c]==1:
        print(c)
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
S = input().lower()
ans = 'None'
for i in range(ord('a'), ord('z')):
    if chr(i) not in S:
        ans = chr(i)
        break
print(ans)

Submission status: Wrong Answer

Solution code:
S = input().lower()
dic = {}
for i, c in enumerate(range(ord('a'), ord('z')+1)):
    dic[chr(c)] = 0
for c in S:
    dic[c] += 1
for k, v in dic.items():
    if v == 0:
        print(k)
        exit()
print('None')