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:
S = sorted(list(set(list(input()))))
cf = [chr(ord("a")+i) for i in range(26)]

for i in range(len(S)):
    if S[i] != cf[i]:
        print(cf[i])
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
s = list(map(str,input()))
s.sort()
cnt = len(list(set(s)))

if cnt != 26:
    x = chr(ord(s[0]) + 1)
    print(x)

else:
    print("None")

Submission status: Wrong Answer

Solution code:
s = list(map(str,input()))
s.sort()
cnt = len(list(set(s)))

if cnt == 26:
    print("None")
else:
    x = chr(ord(s[0]) + 1)
    print(x)

Submission status: Wrong Answer

Solution code:
import sys
S = list(input())
s = list(set(S))
s.sort()
alfa = list('abcdefghijklmnopqrstuvwxyg')
ans = 0
if(len(s)==len(alfa)):
  print('None')
  sys.exit()
else:
  for i in range(len(s)):
    if(s[i]!=alfa[i]):
      print(alfa[i])
      sys.exit()
print(alfa[len(s)])

Submission status: Wrong Answer

Solution code:
import sys
S = list(input())
s = list(set(S))
s.sort()
alfa = list('abcdefghijklmnopqrstuvwxyg')
ans = 0
if(len(s)==len(alfa)):
  print('None')
  sys.exit()
else:
  for i in range(len(s)):
    if(s[i]!=alfa[i]):
      print(alfa[i])
      sys.exit()
  print(alfa[len(s)-1])

Submission status: Wrong Answer

Solution code:
import sys
S = list(input())
s = list(set(S))
s.sort()
alfa = list('abcdefghijklmnopqrstuvwxyg')
ans = 0
if(len(s)==len(alfa)):
  print('None')
  sys.exit()
else:
  for i in range(len(s)):
    if(s[i]!=alfa[i]):
      print(alfa[i])
      sys.exit()
  print(alfa[len(s)])

Submission status: Wrong Answer

Solution code:
import sys
S = list(input())
s = list(set(S))
s.sort()
alfa = list('abcdefghijklmnopqrstuvwxyg')
ans = 0
if(len(s)==len(alfa)):
  print('None')
else:
  for i in range(len(s)):
    if(s[i]!=alfa[i]):
      print(alfa[i])
      sys.exit()
  print(alfa[len(s)])

Submission status: Wrong Answer

Solution code:
import sys
S = list(input())
s = list(set(S))
s.sort()
alfa = list('abcdefghijklmnopqrstuvwxyg')
ans = 0
if(len(s)==len(alfa)):
  print('None')
else:
  for i in range(len(s)):
    if(s[i]!=alfa[i]):
      print(alfa[i])
      sys.exit()
  print('b')

Submission status: Wrong Answer

Solution code:
import sys
S = list(input())
s = list(set(S))
s.sort()
alfa = list('abcdefghijklmnopqrstuvwxyg')
ans = 0
if(len(s)==len(alfa)):
  print('None')
else:
  for i in range(len(s)):
    if(s[i]!=alfa[i]):
      print(alfa[i])
      sys.exit()
  print('a')

Submission status: Wrong Answer

Solution code:
import sys
S = list(input())
s = list(set(S))
s.sort()
alfa = list('abcdefghijklmnopqrstuvwxyg')
ans = 0
if(len(s)==len(alfa)):
  print('None')
else:
  for i in range(len(s)):
    if(s[i]!=alfa[i]):
      print(alfa[i])
      sys.exit()

Submission status: Wrong Answer

Solution code:
import sys
S = list(input())
s = list(set(S))
s.sort()
alfa = [chr(ord("a")+i) for i in range(26)]
ans = 0
if(len(s)==len(alfa)):
  print('None')
else:
  for i in range(len(s)):
    if(s[i]!=alfa[i]):
      print(alfa[i])
      sys.exit()

Submission status: Wrong Answer

Solution code:
import sys
S = list(input())
s = list(set(S))
s.sort()
alfa = [chr(ord("a")+i) for i in range(26)]
ans = 0
if(len(s)==26):
  print('None')
else:
  for i in range(len(s)):
    if(s[i]!=alfa[i]):
      print(alfa[i])
      sys.exit()

Submission status: Wrong Answer

Solution code:
import sys
S = list(input())
s = list(set(S))
s.sort()
alfa = [chr(ord("a")+i) for i in range(26)]
ans = 0
if(len(s)==26):
  print('None')
for i in range(len(s)):
  if(s[i]!=alfa[i]):
    print(alfa[i])
    sys.exit()

Submission status: Wrong Answer

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

Submission status: Wrong Answer

Solution code:
a = list(input())

for i in range(1, len(a)):
    compare = a[0]
    if a[i] < compare:
        a[i] = compare

print(chr(ord(compare) + 1))

Submission status: Wrong Answer

Solution code:
data=['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',]
s=list(input())
t=sorted(s)
i=0
while (t[i]==data[i] and i<25):
    i=i+1
if i<25:
    print(data[i])
else:
    print('None')

Submission status: Wrong Answer

Solution code:
L = [chr(i) for i in range(97, 123)]
f = 0
s = input()
for l in L:
  if s.count(l) == 0:
    print(l)
    f = 1
if f == 0:
  print("None")

Submission status: Wrong Answer

Solution code:
S = list(input())
L = len(S)
Slist = set()
for i in range(L):
    Slist.add(ord(S[i]))
Slist = list(Slist)
Slist.sort()
ans = "None"
j = 0
L = len(Slist)
for i in range(97, 123):
    if Slist[j] == i:
        j += 1
        if j >= L:
            ans = chr(i+1)
            break
        continue
    ans = chr(i)
    break
print(ans)

Submission status: Wrong Answer

Solution code:
a=input()
s=[0]*26
for i in range(len(a)):
    s[ord(a[i])-97]=1
print(chr(s.index(min(s))+97))

Submission status: Wrong Answer

Solution code:
s=input()

for i in "abcdefghijklmnopqrstuvwxyz":
  if i not in s:
    print(i)
    break
    
print("None")

Submission status: Wrong Answer

Solution code:
s=input()

for i in "abcdefghijklmnopqrstuvwxyz":
  if i not in s:
    print(i)
    break
  else:
    print("None")

Submission status: Wrong Answer

Solution code:
s=input()

for i in "abcdefghijklmnopqrstuvwswz":
  if i not in s:
    print(i)
    break
  else:
    print("None")

Submission status: Wrong Answer

Solution code:
S = list(input())

S.sort()

for i in range(len(S)-1):
    if ord(S[i+1]) - ord(S[i]) == 0 or ord(S[i+1]) - ord(S[i]) == 1:
        pass
    else:
        res = ord(S[i]) + 1
        print(chr(res))
        exit()

res = ord(S[-1]) + 1

if S[0] == 'a' and S[-1] == 'z':
    print('None')
elif S[0] != 'a':
    print('a')
else:
    print(chr(res))

Submission status: Wrong Answer

Solution code:
S = list(input())

S.sort()

for i in range(len(S)-1):
    if ord(S[i+1]) - ord(S[i]) == 0 or ord(S[i+1]) - ord(S[i]) == 1:
        pass
    else:
        res = ord(S[i]) + 1
        print(chr(res))
        exit()

res = ord(S[-1]) + 1

if S[0] == 'a' and S[-1] == 'z':
    print('None')
elif S[0] != 'a':
    res = ord(S[0]) - 1
    print(chr(res))
else:
    print(chr(res))

Submission status: Wrong Answer

Solution code:
S = list(input())

S.sort()

for i in range(len(S)-1):
    if ord(S[i+1]) - ord(S[i]) == 0 or ord(S[i+1]) - ord(S[i]) == 1:
        pass
    else:
        res = ord(S[i]) + 1
        print(chr(res))
        exit()

res = ord(S[-1]) + 1

if chr(res) == '{':
    print('None')
else:
    print(chr(res))

Submission status: Wrong Answer

Solution code:
S = input()
S = sorted(S)

dict = ["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"]

cnt = 0
str = ""
ans = "None"
for i in range(len(S)):
    if i == 0:
        if S[i] == "a":
            cnt += 1
            str = "a"
        else:
            ans = "a"
            break
    else:
        if str < S[i]:
            str = S[i]
            if str != dict[cnt]:
                ans = dict[cnt]
                break
            cnt += 1

print(ans)

Submission status: Wrong Answer

Solution code:
S = input()
S = sorted(S)

dict = ["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"]

cnt = 0
str = ""
ans = "a"
for i in range(len(S)):
    if i == 0 and S[i] == "a":
        cnt += 1
        str = "a"
    else:
        if str < S[i]:
            str = S[i]
            if str != dict[cnt]:
                ans = dict[cnt]
                break
            cnt += 1

if cnt >= 26:
    print("None")
else:
    print(ans)

Submission status: Wrong Answer

Solution code:
S = input()
S = sorted(S)

dict = ["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"]

cnt = 0
str = ""
ans = None
for i in range(len(S)):
    if i == 0 and S[i] == "a":
        cnt += 1
        str = "a"
    else:
        if str < S[i]:
            str = S[i]
            if str != dict[cnt]:
                ans = dict[cnt]
                break
            cnt += 1

print(ans)

Submission status: Wrong Answer

Solution code:
s = input()
alpha = "abcdefghijklmnopqrstuvwxz"
for a in alpha:
    if a not in s:
        print(a)
        break
else:
    print("None")

Submission status: Wrong Answer

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

Submission status: Wrong Answer

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

Submission status: Wrong Answer

Solution code:
S = input()
S = sorted(S)
for i in range(97, 123):
    if S.count(chr(i)) > 0:
      continue
    else:
      print(chr(i))
      break

Submission status: Wrong Answer

Solution code:
s=input()
l='abcdefghijklmnopqrstuvwxyz'
s=''.join(list(set(s)))
s=sorted(s)
f=0
r='None'
for i in range(len(s)):
    if(s[i]!=l[i]):
        r=l[i]
        f=1
        break
print(r)

Submission status: Wrong Answer

Solution code:
s = input()

for i in range(26):
    x = chr(i + 97)
    if not x in s:
        print(x)
        exit()

Submission status: Wrong Answer

Solution code:
S = [i for i in input()]
S = set(S)
S = sorted(list(S))
for i in range(97, 122):
    if chr(i) not in S:
        print(chr(i))
        exit(0)
else:
    print('None')

Submission status: Wrong Answer

Solution code:
S = [i for i in input()]
for i in range(97, 122):
    if chr(i) not in S:
        print(chr(i))
        exit(0)
else:
    print('None')

Submission status: Wrong Answer

Solution code:
s = input()

import string
a = list(string.ascii_lowercase)

for i in range(25):
    if s.count(a[i]) == 0:
        print(a[i])
        break
    else:
        print('None')

Submission status: Wrong Answer

Solution code:
s = input()

import string
a = list(string.ascii_lowercase)

for i in range(26):
    if s.count(a[i]) == 0:
        print(a[i])
        break

Submission status: Wrong Answer

Solution code:
L=list(input())
L=list(set(L))
L=sorted(L)
R=["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 range(min(26,len(L))):
  if L[i]!=R[i]:
    print(R[i])
    exit()
print("None")

Submission status: Wrong Answer

Solution code:
a = ["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"]
b = input()
c = []
d = len(b)

for i in range(int(d)):
  c.append(b[i])

e = list(set(c))
f = sorted(e)
g = len(f)
h = int(0)

if g != 26:
  for i in range(int(g)):
    if f[i] == a[i]:
      h = h + 1
    else:
      print(a[i])
else:
  print("None")
  
if h == g:
  print(a[h])

Submission status: Wrong Answer

Solution code:
a = ["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"]
b = input()
c = []
d = len(b)

for i in range(int(d)):
  c.append(b[i])

e = list(set(c))
f = sorted(e)
g = len(f)
h = int(0)

for i in range(int(g)):
  if f[i] == a[i]:
    pass
  else:
    print(a[i])
    h = h + 1
    break

if h == 0:
  print("None")

Submission status: Wrong Answer

Solution code:
S = set(input())
a = set([chr(i) for i in range(ord('a'), ord('z')+1)])
result = sorted(list(a-S))
if len(result) == 0:
    print('None')
else:
    print([0])

Submission status: Wrong Answer

Solution code:
S = input()
S = set(S)
S = list(S)
S.sort()
if len(S) <= 26:
    for _ in range(26):
        S.append("z")
X = [chr(i) for i in range(97, 97 + 26)]
for a, b in zip(S, X):
    if a != b:
        print(b)
        break
else:
    print("None")

Submission status: Wrong Answer

Solution code:
#k = int(input())
#s = input()
#a, b = map(int, input().split())
#s, t = map(str, input().split())
#l = list(map(int, input().split()))
#l = [list(map(int,input().split())) for i in range(n)]
#a = [list(input()) for _ in range(n)]
#a = [int(input()) for _ in range(n)]


#hashでカウンタを格納する
#ソートして、要素がインクリメントされない箇所を検出する

s = input()

s = sorted(s)
#print(s)

last = ord(s[0])
for i in range(1, len(s)):
    if ord(s[i]) == last:
        pass
    elif ord(s[i]) == last + 1:
        last = ord(s[i])
    else:
        print(chr(last+1))
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
S = input()
S = set(S)
S = list(S)
S.sort()
X = [chr(i) for i in range(97, 97 + 26)]
for a, b in zip(S, X):
    if a != b:
        print(b)
        break
else:
    print("None")

Submission status: Wrong Answer

Solution code:
import string
al = string.ascii_lowercase

S = set(input())

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

Submission status: Wrong Answer

Solution code:
S=list(set(input()))
S.sort()
import string
switch=True
A=list(string.ascii_lowercase)
for i in range(len(S)):
    if not S[i]==A[i]:
        print(A[i])
        switch=False
        break
if switch:
    print("None")

Submission status: Wrong Answer

Solution code:
S=list(set(input()))
S.sort()
import string
A=list(string.ascii_lowercase)
for i in range(len(S)):
    if not S[i]==A[i]:
        print(A[i])
        break
    else:
        print("None")

Submission status: Wrong Answer

Solution code:
S=list(set(input()))
S.sort()
import string
A=list(string.ascii_lowercase)
for i in range(len(S)):
    if not S[i]==A[i]:
        print(A[i])
        break

Submission status: Wrong Answer

Solution code:
str1 = input()
li = list(str1)
anli = []
for i in range(26):
    anli.append(0)
for i in range(len(li)):
   anli[ord(li[i]) - 97] += 1
flag = True
mi = 27
print(anli)
for i in range(len(anli)):
    if anli[i] == 0:
        flag = False
        mi = min(i,mi)
if flag:
    print('None')
else:
    print(chr(mi+97))

Submission status: Wrong Answer

Solution code:
Sset=set(input())
Sset=sorted(Sset)

ans = "None"
for i,c in enumerate(Sset):
	if i+97 !=ord(c):
		ans = chr(i+97)
		break

print(ans)

Submission status: Wrong Answer

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

for i in range(26):
    if cc[alphabet[i]]==0:
        print(alphabet[i])
        exit()
    if i==25:
        print('None')
        exit()

Submission status: Wrong Answer

Solution code:
S = input()
List = list(S)
s_l = set(List)
n = 10
res= ""
flag = False
for i in range(97,123):
  print(chr(i))
  if not chr(i) in s_l:
    res = chr(i)
    flag = True
    break
if flag:
  print(res)
else:
  print("None")

Submission status: Wrong Answer

Solution code:
S = input()
List = list(S)
s_l = set(List)
n = 10
res= ""
flag = False
for i in range(97,124):
  if not chr(i) in s_l:
    res = chr(i)
    flag = True
    break
if flag:
  print(res)
else:
  print("None")

Submission status: Wrong Answer

Solution code:
S = input()
List = list(S)
s_l = set(List)
n = 10
res= ""
flag = False
for i in range(97,113):
  if not chr(i) in s_l:
    res = chr(i)
    flag = True
    break
if flag:
  print(res)
else:
  print("None")

Submission status: Wrong Answer

Solution code:
S = input()
List = list(S)
s_l = set(List)
n = 10
res= ""
for i in range(97,113):
  if not chr(i) in s_l:
    res = chr(i)
    break
print(res)

Submission status: Wrong Answer

Solution code:
s = list(str(input()))
s.sort()
a = [chr(ord('a') + i) for i in range(26)]
b = {}
for i in a:
    b[i] = 0
for i in s:
    b[i] += 1

alf = ''
for i in a:
    if b[i] == 0:
        print(i)
        alf = i
        break
if alf:
    print(i)
else:
    print('None')

Submission status: Wrong Answer

Solution code:
S = input()
alp = list('abcdefghijklmnopqrstuvwxyz')
print(alp)
for i in range(len(S)):
  if S[i] in alp:
    alp.remove(S[i])
if len(alp) == 0:
  print('None')
else:
  print(alp[0])

Submission status: Wrong Answer

Solution code:
s = list(input())

s.sort()

for i in range(97,123):
    if s.count(chr(i)) == 0:
        print(chr(i))
        break

Submission status: Wrong Answer

Solution code:
p = input()

s = list(p)
s.sort()

answer = -1
count = 0

for i in range(len(s)):
    x = ord(s[i])
    if x < 97 + count:
        continue
    else:
        if x == 97 + count:
            count += 1
            continue
        else:
            answer = chr(97 + count)
            break

if answer == -1:
    print('None')
else:
    print(answer)

Submission status: Wrong Answer

Solution code:
s = sorted(input())
for i in range(len(s)-1):
  if ord(s[i+1])-ord(s[i])>=2:
    print(chr(ord(s[i])+1))
    quit()
print('None')

Submission status: Wrong Answer

Solution code:
import sys
s = input()
for one in range(97,97+26):
    c = chr(one)
    print(c)
    if not c in s:
        print(c)
        sys.exit()
print("None")

Submission status: Wrong Answer

Solution code:
import sys
s = input()
for one in range(97,110):
    c = chr(one)
    if not c in s:
        print(c)
        sys.exit()
print("None")

Submission status: Wrong Answer

Solution code:
N=list(input())
s=set(N)
ans=''.join(sorted(s))
if len(ans)==1 and ans[0]=='a':
  print('b')
  exit()
all=[chr(i) for i in range(97,97+26)]
for i in range(len(ans)):
  if ans[i]!=all[i]:
    print(all[i])
    exit()
print('None')

Submission status: Wrong Answer

Solution code:
N=list(input())
s=set(N)
ans=''.join(sorted(s))
all=[chr(i) for i in range(97,97+26)]
for i in range(len(ans)):
  if ans[i]!=all[i]:
    print(all[i])
    exit()
print('None')

Submission status: Wrong Answer

Solution code:
A="abcdefghijklmnopqrstuvwxyz"
S=input()
S=sorted(set(S))
for i in range(len(S)):
	if S[i]!=A[i]:
		print(A[i])
		exit()
print("None")

Submission status: Wrong Answer

Solution code:
S = input()

for n in range(97,112):
  if chr(n) not in S:
    print(chr(n))
    exit()

print("None")

Submission status: Wrong Answer

Solution code:
S = set(input())
for i in range(97, 122):
    if chr(i) not in S:
        print(chr(i))
        exit()
print('None')

Submission status: Wrong Answer

Solution code:
alp = 'abcdefghijklmnopqrstuvwxyz'

d = {c:False for c in alp}

s = open(0).read().rstrip()

for c in list(s):
    d[c] = True

for c,b in d.items():
    if not b:
        print(c)
        break

Submission status: Wrong Answer

Solution code:
s = input()
s = sorted(s)
s = set(s)
alpha = 'a'
flg = 0
for i in range(1,26):
    if (alpha not in s):
        flg = 1
        break
    else : alpha = chr(ord(alpha)+1)
if (flg): print(alpha)
else: print("None")

Submission status: Wrong Answer

Solution code:
s = input()
for i in range(97, 123):
    print(i, chr(i))
    if s.find(chr(i)) == -1:
        print(chr(i))
        exit()
    
print('None')

Submission status: Wrong Answer

Solution code:
s = input()
for i in range(97, 114+1):
    if s.find(chr(i)) == -1:
        print(chr(i))
        exit()
    
print('None')

Submission status: Wrong Answer

Solution code:
s = input()
for i in range(97, 113+1):
    if s.find(chr(i)) == -1:
        print(chr(i))
        exit()
    
print('None')

Submission status: Wrong Answer

Solution code:
def i():
	return int(input())
def i2():
	return map(int,input().split())
def s():
	return str(input())
def l():
	return list(input())
def intl():
	return list(int(k) for k in input().split())

s = l()
alf = "abcdefghijklmnopqrstuvwxyz"
for i in range(len(s)):
	alf = alf.strip(s[i])
if alf == "":
	print("None")
else:
	print(alf[0])

Submission status: Wrong Answer

Solution code:
def i():
	return int(input())
def i2():
	return map(int,input().split())
def s():
	return str(input())
def l():
	return list(input())
def intl():
	return list(int(k) for k in input().split())

s = l()
alf = "abcdefghijklmnopqrstuvwxyz"
for i in range(len(s)):
	alf = alf.replace(s[i],"")
print(alf)
if alf == "":
	print("None")
else:
	print(alf[0])

Submission status: Wrong Answer

Solution code:
import sys
import math
def I():return int(sys.stdin.readline().replace("\n",""))
def I2():return map(int,sys.stdin.readline().replace("\n","").split())
def S():return str(sys.stdin.readline().replace("\n",""))
def L():return list(sys.stdin.readline().replace("\n",""))
def Intl():return [int(k) for k in sys.stdin.readline().replace("\n","").split()]
def Lx(k):return list(map(lambda x:int(x)*-k,sys.stdin.readline().replace("\n","").split()))

if __name__ == "__main__":
    alpha = "abcdefghijklmnopqrstuvwxyz"
    inp = S()
    for i in inp:
        alpha = alpha.strip(i)
    print(alpha[0] if len(alpha) > 0 else "None")

Submission status: Wrong Answer

Solution code:
import string
import sys
a = string.ascii_lowercase
S =sys.stdin.readline()
a = sorted(set(a)^set(S))
if a:
    print(a[0])
else:
    print("None")

Submission status: Wrong Answer

Solution code:
S = input()
lis_S = list(S)

a = "abcdefghijklmnopqrstuvwxyz"

for i in lis_S:
    a = a.strip(i)

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

Submission status: Wrong Answer

Solution code:
S = input()
lll = "abcdefghijklmnopqrstuvwxyz"
for i in range(26):
    if lll[i] in S:
        print(lll[i])
        exit()
    else:
        pass
    
print("None")

Submission status: Wrong Answer

Solution code:
s = list(input())
exist = 'abcdefghijklmnopqrstuvwxyz'

j = 0
s = set(s)
s = sorted(s)

for i in s:
    if i == exist[j]:
        pass    
    elif i != exist[j]:
        print(exist[j])
        break
    if j+1 == len(s):
        print('None')
    j += 1

Submission status: Wrong Answer

Solution code:
s = list(input())
exist = 'abcdefghijklmnopqrstuvwxyz'
if len(s) == len(exist):
    print('None')
    exit()

j = 0
s = set(s)
s = sorted(s)

for i in s:
    if i == exist[j]:
        pass    
    elif i != exist[j]:
        print(exist[j])
        break
    j += 1

Submission status: Wrong Answer

Solution code:
s=input()
x=ord('a')
z=0
for i in range(x,x+27):
    y=chr(i)
    if y not in s:
        print(y)
        z=1
        break
if z==0:
    print('None')

Submission status: Wrong Answer

Solution code:
s=input()
x=ord('a')
for i in range(x,x+27):
    y=chr(i)
    if y not in s:
        print(y)
        break

Submission status: Wrong Answer

Solution code:
S = list(input())
S. sort()

if S[len(S)-1] == "z":
  print("None")
else:
  print(chr(ord(S[len(S)-1])+1))

Submission status: Wrong Answer

Solution code:
S=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 l in L:
    if S.count(l)>0:
        pass
    else:
        print(l)
else:
    print("None")

Submission status: Wrong Answer

Solution code:
import math
from collections import deque
from collections import defaultdict

import bisect

#自作関数群
def readInt():
	return int(input())
def readInts():
	return list(map(int, input().split()))
def readChar():
	return input()
def readChars():
	return input().split()
def factorization(n):
	res = []
	if n%2==0:
		res.append(2)
	for i in range(3,math.floor(n//2)+1,2):
		if n%i==0:
			c = 0
			for j in res:
				if i%j==0:
					c=1
			if c==0:
				res.append(i)
	return res
def fact2(n):
	p = factorization(n)
	res = []
	for i in p:
		c=0
		z=n
		while 1:
			if z%i==0:
				c+=1
				z/=i
			else:
				break
		res.append([i,c])
	return res
def fact(n):#階乗
	ans = 1
	m=n
	for _i in range(n-1):
		ans*=m
		m-=1
	return ans
def comb(n,r):#コンビネーション
	if n<r:
		return 0
	l = min(r,n-r)
	m=n
	u=1
	for _i in range(l):
		u*=m
		m-=1
	return u//fact(l)
def combmod(n,r,mod):
	return (fact(n)/fact(n-r)*pow(fact(r),mod-2,mod))%mod
def printQueue(q):
	r=copyQueue(q)
	ans=[0]*r.qsize()
	for i in range(r.qsize()-1,-1,-1):
		ans[i] = r.get()
	print(ans)
class UnionFind():
	def __init__(self, n):
		self.n = n
		self.parents = [-1]*n

	def find(self, x): # root
		if self.parents[x]<0:
			return x
		else:
			self.parents[x] = self.find(self.parents[x])
			return self.parents[x]

	def union(self,x,y):
		x = self.find(x)
		y = self.find(y)

		if x==y:
			return

		if self.parents[x]>self.parents[y]:
			x,y = y,x

		self.parents[x]+=self.parents[y]
		self.parents[y]=x

	def size(self,x):
		return -1*self.parents[self.find(x)]

	def same(self,x,y):
		return self.find(x)==self.find(y)

	def members(self,x): # much time
		root = self.find(x)
		return [i for i in range(self.n) if self.find(i)==root]

	def roots(self):
		return [i for i,x in enumerate(self.parents) if x<0]

	def group_count(self):
		return len(self.roots())

	def all_group_members(self):
		return {r: self.members(r) for r in self.roots()} # 1~n
def bitArr(n):#ビット全探索
	x = 1
	zero = "0"*n
	ans = []
	ans.append([0]*n)
	for i in range(2**n-1):
		ans.append(list(map(lambda x:int(x),list((zero+bin(x)[2:])[-1*n:]))))
		x+=1
	return ans;
def arrsSum(a1,a2):
	for i in range(len(a1)):
		a1[i]+=a2[i]
	return a1
def maxValue(a,b,v):
	v2 = v
	for i in range(v2,-1,-1):
		for j in range(v2//a+1): #j:aの個数
			k = i-a*j
			if k%b==0:
				return i
	return -1
def copyQueue(q):
	nq = queue.Queue()
	n = q.qsize()
	for i in range(n):
		x = q.get()
		q.put(x)
		nq.put(x)
	return nq
def get_sieve_of_eratosthenes(n):
	#data = [2]
	data = [0,0,0]
	for i in range(3,n+1,2):
		data.append(i)
		data.append(0)
	for i in range(len(data)):
		interval = data[i]
		if interval!=0:
			for j in range(i+interval,n-1,interval):
				data[j] = 0
	#ans = [x for x in data if x!=0]
	ans = data[:]
	return ans

def isInt(n):
	if isinstance(n, int):
		return True
	else:
		return n.is_integer()

s = readChar()

ex = set()

for i in s:
	ex.add(i)

al = ["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 range(len(ex)):
	al.remove(ex.pop())

if len(al)==0:
	print(-1)
else:
	print(al[0])

Submission status: Wrong Answer

Solution code:
s=input()
al="abcdefghijklmnopqrstuvwxyz"
ans="None"
for i in al:
  dumy=s.count(i)
  if dumy:
    ans=i
    break

print(ans)

Submission status: Wrong Answer

Solution code:
s = input()
c = set()
for i in range(len(s)):
  c.add(s[i])
c = list(c)
c.sort()
abc = ['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']
ans = ''
for e in abc:
  if e not in c:
    ans = e
    break
if ans == '':
  print('None')

Submission status: Wrong Answer

Solution code:
s = input()
c = set()
for i in range(len(s)):
  c.add(s[i])
c = list(c)
c.sort()
abc = ['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 e in abc:
  if e not in c:
    print(e)
    break
if e == 'z':
  print('None')

Submission status: Wrong Answer

Solution code:
def main():
    dicts = {'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}
    s = input()
    for i in s:
        dicts[i] = dicts[i]+1
    for k,v in dicts.items():
        if v==0:
            print(k)
            return
    print('None')
main()

Submission status: Wrong Answer

Solution code:
def main():
    dicts = {'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}
    s = input()
    for i in s:
        dicts[i] = dicts[i]+1
    for k,v in dicts.items():
        if v==0:
            print(k)
            break
main()

Submission status: Wrong Answer

Solution code:
s=input()
sset=set(s)
list1=list(range(97,123))
for i in range(len(sset)):
    str1=sset.pop()
    list1.remove(ord(str1))
if len(list1)==0:
    print("None")
else:
    print(list1[0])

Submission status: Wrong Answer

Solution code:
if __name__ == '__main__':
    a = input()
    count = 0

    for i in range(24):
        s = chr(97+i)
        if s in a:
            count+=1
        else:
            print(s)
            break

    if count == 24:
        print("None")

Submission status: Wrong Answer

Solution code:
if __name__ == '__main__':
    a = input()
    count = 0

    for i in range(25):
        s = chr(97+i)
        if s in a:
            count+=1
        else:
            print(s)
            break

    if count == 25:
        print("None")

Submission status: Wrong Answer

Solution code:
s = list(set(input()))
s.sort()

for i in range(len(s)-1):
    if 1 < abs((ord(s[i]) - ord(s[i+1]))):
        print(chr(ord(s[i])+1))
        exit()
print('None')

Submission status: Wrong Answer

Solution code:
s=list(input())
s=list(set(s))
s.sort()
import string
l=string.ascii_lowercase
ans="None"
for i in range(len(s)):
  if s[i]!=l[i]:
    ans=l[i]
    break
if len(s)==1 and s[0]=="a":
  ans="b"
print(ans)

Submission status: Wrong Answer

Solution code:
s=list(input())
s=list(set(s))
s.sort()
import string
l=string.ascii_lowercase
ans="None"
for i in range(len(s)):
  if s[i]!=l[i]:
    ans=l[i]
    break
if len(s)==1:
  ans="a"
print(ans)

Submission status: Wrong Answer

Solution code:
s=list(input())
s=list(set(s))
s.sort()
import string
l=string.ascii_lowercase
ans="None"
for i in range(len(s)):
  if s[i]!=l[i]:
    ans=l[i]
    break
print(ans)

Submission status: Wrong Answer

Solution code:
s=list(input())
s=list(set(s))
s.sort()
print(s)
import string
l=string.ascii_lowercase
ans="None"
for i in range(len(s)):
  if s[i]!=l[i]:
    ans=l[i]
    break
print(ans)

Submission status: Wrong Answer

Solution code:
s = input()
for i in range(ord('a'), ord('z') + 1):
  c = chr(i)
  if s.count(c) > 0:
    print(c)
    break
else:
  print('None')

Submission status: Wrong Answer

Solution code:
list=[chr(i) for i in range(97, 97+26)]
S=input()
S=set(S)
A=[x for x in S]
A=sorted(A)
for i in range(len(A)):
    if A[i] == list[i]:
        pass
    else:
        print(list[i])
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
list=[chr(i) for i in range(97, 97+26)]
S=input()
S=set(S)
A=[x for x in S]
A=sorted(A)
for i in range(len(S)):
    if A[i] == list[i]:
        pass
    else:
        print(list[i])
        exit()
print("None")

Submission status: Wrong Answer

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

res = ord(S[0])
for i in range(1,len(S)):
    if res+1 == ord(S[i]):
        res = ord(S[i])
    else:
        print(chr(res+1))
        break
else:
    print('None')

Submission status: Wrong Answer

Solution code:
s = input()

for i in range(1,26):
    if chr(97+i) not in s:
        print(chr(97+i))
        exit()
print("None")