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=input()
a=sorted(set(s))
E="abcdefghijklmnopqrstuvwxyz"
ans=0
count=0
for i in range(len(set(s))):
  if a[i]!=E[i]:
    ans=i
    break
  else:
    count+=1
print(E[ans] if count<26 else "None")

Submission status: Wrong Answer

Solution code:
s=input()
a=sorted(set(s))
E="abcdefghijklmnopqrstuvwxyz"
ans=0
for i in range(len(set(s))):
  if a[i]!=E[i]:
    ans=i
    break
print(E[ans] if ans>0 else "None")

Submission status: Wrong Answer

Solution code:
S = input().rstrip()
element = [0]*len(S)
for i in range(len(S)):
    s = ord(S[i]) - ord("a")
    element[s] += 1
zero = element.count(0)
print("None" if zero == 0 else chr(ord("a") + element.index(0)))

Submission status: Wrong Answer

Solution code:
S = input()

alphabets = [chr(i) for i in range(97,97+26)]

setS = sorted(set(S))
for A in alphabets:
  if A not in setS:
    print(A)
  else: continue
print('None')

Submission status: Wrong Answer

Solution code:
l=[chr(i) for i in range(65,65+26)]
s=list(input())
a=set(l)-set(s)
a=list(a)
a.sort()
print(a[0])

Submission status: Wrong Answer

Solution code:
s = input()
listA = ["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(27):
  if s.count("listA[i]")==0:
    print(listA[i])
    break

Submission status: Wrong Answer

Solution code:
s = input()
a = list("abcdefghijklmnopqrstuvwxyz")
for i in range(len(a)):
    if s.count(a[i]):
        break
    else:
        print(a[i])
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
S = list(input())
alphabet = list('abcdefghijklmnopqrstuvwxyz')
bucket = {}
for a in alphabet:
  bucket[a] = 0
for s in S:
  bucket[s] += 1
for a in alphabet:
  if bucket[a] == 0:
    print(a)
    break
print('None')

Submission status: Wrong Answer

Solution code:
S = list(input())
alphabet = list('abcdefghijklmnopqrstuvwxyz')
bucket = {}
for a in alphabet:
  bucket[a] = 0
for s in S:
  bucket[s] += 1
for a in alphabet:
  if bucket[a] == 0:
    print(a)
    break

Submission status: Wrong Answer

Solution code:
s=input()

L=list(s)

X=[0]*150
for i in L:
    X[ord(i)]+=1

ans='None'
for j in range(97,124):
    if X[j]==0:
        ans=chr(j)
        break

print(ans)

Submission status: Wrong Answer

Solution code:
s=input()

L=list(s)

X=[0]*150
for i in L:
    X[ord(i)]+=1

ans='None'
for j in range(97,150):
    if X[j]==0:
        ans=chr(j)
        break

print(ans)

Submission status: Wrong Answer

Solution code:
S = input()
for i in range(ord('a'), ord('z')+1):
    c = chr(i)
    if c not in S:
        print(c)

    if c == 'z':
        print("None")

Submission status: Wrong Answer

Solution code:
# python template for atcoder1
import sys
sys.setrecursionlimit(10**9)
input = sys.stdin.readline
s = input()
alpha = [chr(i) for i in range(97, 97+26)]
for c in alpha:
    if c in s:
        continue
    else:
        print(c)
        break

Submission status: Wrong Answer

Solution code:
# coding: utf-8
S = input()
s = [chr(97 + i) for i in range(26)]
for i in s:
    if i not in S:
        print(i)
        break

Submission status: Wrong Answer

Solution code:
s = input()
result_s = sorted(s)
atoz = 'abcdefghjklmnopqrstuvwxyz'
if atoz in s:
    print("None")
else:
    print(result_s[0])

Submission status: Wrong Answer

Solution code:
S = input()
S = list(S)
S = set(S)
S = list(S)
S.sort()
alpabet = 'abcdefghijklmnopqrstuvwxyz'
alphabet = list(alpabet)
count = 0

if(len(S) == 26):
  print('None')
else:
  for i in range(len(S)):
   count += 1
   if(S[i] != alphabet[i]):
      print(alphabet[i])
      break
  if(count == len(S)):
    print(alphabet[count])

Submission status: Wrong Answer

Solution code:
S = input()
S = list(S)
S = set(S)
S = list(S)
S.sort()
alpabet = 'abcdefghijklmnopqrstuvwxyz'
alphabet = list(alpabet)

if(len(S) == 26):
  print('None')
else:
  for i in range(len(S)):
   if(S[i] != alphabet[i]):
      print(alphabet[i])
      break

Submission status: Wrong Answer

Solution code:
print(min(set(map(chr,range(97,123)))-set(input())or'None'))

Submission status: Wrong Answer

Solution code:
s = set(list(input()))
alp = list("abcdefghijklmnopqrstuvwxyz")
if len(s) == len(alp):
    print("None")
    exit()
s = sorted(s)
for c, a in zip(s, alp):
    if c != a:
        print(a)
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
s = set(list(input()))
alp = list("abcdefghijklmnopqrstuvwxyz")
if len(s) == len(alp):
    print("None")
    exit()
s = sorted(s)
for c, a in zip(s, alp):
    if c != a:
        print(a)
        break

Submission status: Wrong Answer

Solution code:
s = input()
alphabet = "abcdefghijklmnopqrstuvwxyz"
flag = 0
for s in alphabet:
  if s.count(s) == 0:
    print(s)
    break
  else:flag += 1

if flag ==26:print("None")

Submission status: Wrong Answer

Solution code:
# 072B
s = sorted(set(input()))
abc = 'abcdefghijklmnopqrstuvwxyz'
for a in abc:
    if s.count(a)==0:
        print(a)
        break

Submission status: Wrong Answer

Solution code:
import sys
a=[0]*26
s=input()
for i in range(len(s)):
    a[ord(s[i])-97]=1
    print(a)
    if 0 not in a:
        print('None')
        sys.exit(0)
for i in range(26):
    print(i)
    if a[i]==0:
        print(chr(i+97))
        break

Submission status: Wrong Answer

Solution code:
import sys
a=[0]*26
s=input()
for i in range(len(s)):
    a[ord(s[i])-97]=1
    if 0 not in a:
        print('None')
        sys.exit(0)
    print(a)
for i in range(26):
    if a[i]==0:
        print(chr(i+97))
        break

Submission status: Wrong Answer

Solution code:
import sys
a=[0]*26
s=input()
for i in range(len(s)):
    a[ord(s[i])-97]=1
    if 0 not in a:
        print('None')
        sys.exit(0)
        
for i in range(25):
    if a[i]==0:
        print(chr(i+97))
        break

Submission status: Wrong Answer

Solution code:
s = sorted(set(list(str(input()))))
t = "abcdefghijklmnopqrstuvwxyz"
if len(s) == 26:
    print("None")
for i in range(26):
    if t[i] != s[i]:
        print(t[i])
        break
    elif len(s) == 25:
        print("z")
        break

Submission status: Wrong Answer

Solution code:
alp="abcdefghijklmnopqrstuvwxyz"
lst=[]
for i in input():
    lst.append(i)
lst=sorted(set(lst))
for u in range(len(lst)):
    if lst[u] != alp[u]:
        print(alp[u])
        exit()
print('None')

Submission status: Wrong Answer

Solution code:
alphabets = [i for i in range(ord('a'), ord('z') + 1)]
lists = [ord(i) for i in input()]
lists=list(set(lists))
lists.sort()
for i in range(len(alphabets)):
    try:
        if alphabets[i]!=lists[i]:
            print(chr(alphabets[i]))
            exit(0)
    except:
        print(chr(alphabets[i]))
        exit(0)

print('None')

Submission status: Wrong Answer

Solution code:
s = input()

ans = 'None'
for i in range(ord('a'), ord('n')+1):
  if chr(i) not in s:
    ans = chr(i)
    break
print(ans)

Submission status: Wrong Answer

Solution code:
from collections import  Counter
s = sorted(str(input()))
s = list(s)
l = list(Counter(s))
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']

if len(l) == 26:
    print('None')
else:
    for i in range(len(l)):
        if l[i] != a[i]:
            print(a[i])
            break

Submission status: Wrong Answer

Solution code:
from collections import  Counter
s = sorted(str(input()))
s=list(s)
l = list(Counter(s))
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']

if len(l) == 26:
    print('None')
else:
    for i in range(len(l)):
        if l[i] != a[i]:
            print(a[i])
            break

Submission status: Wrong Answer

Solution code:
from collections import  Counter
s = sorted(str(input()))
l = list(Counter(s))
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']

if len(l) == 26:
    print('None')
else:
    for i in range(len(l)):
        if l[i]!=a[i]:
            print(a[i])
            break

Submission status: Wrong Answer

Solution code:
from collections import  Counter
s = sorted(str(input()))
l = list(Counter(s))
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']

if l==a:
    print('None')
else:
    for i in range(len(l)-1):
        if l[i]!=a[i]:
            print(a[i])
            break

Submission status: Wrong Answer

Solution code:
from collections import  Counter
s = sorted(str(input()))
l = list(Counter(s))
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']

if l==a:
    print('None')
else:
    for i in range(len(l)+1):
        if l[i]!=a[i]:
            print(a[i])
            break

Submission status: Wrong Answer

Solution code:
from collections import  Counter
s = sorted(str(input()))
l = list(Counter(s))
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']

if l==a:
    print('None')
else:
    for i in range(len(l)):
        if l[i]!=a[i]:
            print(a[i])
            break

Submission status: Wrong Answer

Solution code:
from collections import  Counter
s = sorted(str(input()))
l = list(Counter(s))
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']

if l==a:
    print('None')
    
for i in range(len(l)):
        if l[i]!=a[i]:
            print(a[i])
            break

Submission status: Wrong Answer

Solution code:
from collections import  Counter
s = sorted(str(input()))
l = list(Counter(s))
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']
for i in range(0,len(l)):
        if l[i]!=a[i]:
            print(a[i])
            break

if l==a:
    print('None')

Submission status: Wrong Answer

Solution code:
from collections import  Counter
s = sorted(str(input()))
l = list(Counter(s))
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']
for i in range(0,len(l)):
        if l[i]!=a[i]:
            print(a[i])
            break

Submission status: Wrong Answer

Solution code:
from collections import  Counter
s = sorted(str(input()))
l = list(Counter(s))
print(l)
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']
for i in range(0,len(l)):
        if l[i]!=a[i]:
            print(a[i])
            break

Submission status: Wrong Answer

Solution code:
import string


def main():
    s = input()
    for si in string.ascii_lowercase:
        if si not in s:
            print(si)
            break


if __name__ == '__main__':
    main()

Submission status: Wrong Answer

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

if len(s) == 26:
        print('None')

else:
    for i in range(len(s)):
        if s[i] != d[i]:
            print(d[i])
            break

Submission status: Wrong Answer

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

ans = 0
count = 0
for i in range(len(s)):
    if s[i] != d[i]:
        ans = d[i]
        break
    else:
        count += 1
        
if count == 26:
    print('None')
else:
    print(ans)

Submission status: Wrong Answer

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

for i in range(len(s)):
    if s[i] != d[i]:
        print(d[i])
        break
    else:
        print('None')
        break

Submission status: Wrong Answer

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

for i in range(len(s)):
    if s[i] != d[i]:
        print(d[i])
        break

Submission status: Wrong Answer

Solution code:
import sys
# A,B,C = [int(n) for n in input().split()]
# N = int(input())
# A = [0]*N
# for i in range(N):
#     A[i] = int(input())
S = str(input())
ll = list("abcdefghijklmnopqrstuvwxyz")
for al in ll:
    if not (al in S):
        print(al)
        sys.exit()

Submission status: Wrong Answer

Solution code:
import sys
# A,B,C = [int(n) for n in input().split()]
# N = int(input())
# A = [0]*N
# for i in range(N):
#     A[i] = int(input())
S = str(input())
ll = list("asbcdefghijklmnopqrstuvwxyz")
for al in ll:
    if not (al in S):
        print(al)
        sys.exit()

Submission status: Wrong Answer

Solution code:
s =  sorted(set(input()))
ans = 0
ct = 0 
for i in range(len(s)):
 s[i] = ord(s[i])
 ct += 1 
 if ct == len(s):
  print(chr(s[i] +1)) 
  break 
 if ord(s[i+1]) != s[i] +1:
  ans = s[i] +1
  print(chr(ans))
  break
 if ct == 25:
  print('None') 
  break

Submission status: Wrong Answer

Solution code:
S = str(input())
O = "abcdefghijklmnopqrstuvwxyz"
for A in range(26):
    if O[A] in S is False:
        print(O[A])
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
s=list(input())
s.sort()
print("".join(s))

Submission status: Wrong Answer

Solution code:
s = input()
ans = 'a'
for i in range(25):
    if ans not in s:
        print(ans)
        exit()
    ans = chr(ord(ans) + 1)
print("None")

Submission status: Wrong Answer

Solution code:
import sys


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


S = sorted(ii(str))
if len(S) == 26:
    print("None")
    exit()
for i in range(97, 97 + 26):
    if chr(i) not in S:
        print(chr(i))
        exit()

Submission status: Wrong Answer

Solution code:
import sys
from collections import OrderedDict


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


S = ii(str)
alpha = OrderedDict({chr(i): 0 for i in range(97, 97 + 26)})
for s in S:
    alpha[s] += 1
for a in alpha:
    if alpha[a] == 0:
        print(a)
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
import sys


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


S = ii(str)
alpha = {chr(i): 0 for i in range(97, 97 + 26)}
for s in S:
    alpha[s] += 1
for a in alpha:
    if alpha[a] == 0:
        print(a)
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
import string
pp = list(input())
pp=list(set(pp))
pp.sort()
pp.append("1")
print(pp)
s = ""
x = list(string.ascii_lowercase)
x.append("None")
for j in range(len(pp)):
    if pp[j] != x[j]: 
        s = x[j]
        break
    elif pp[j] =="1":
        s = "None"
print(s)

Submission status: Wrong Answer

Solution code:
import string
pp = list(input())
pp.sort()
for i in string.ascii_lowercase:
    if i != pp[0]:
        print(i)
        break
print("None")

Submission status: Wrong Answer

Solution code:
import string
pp = list(input())
pp.sort()
for i in string.ascii_lowercase:
    if i != pp[0]:
        print(i)
        break
    print("None")

Submission status: Wrong Answer

Solution code:
import string
pp = list(input())
pp.sort()
for i in string.ascii_lowercase:
    if i != pp[0]:
        print(i)
        break

Submission status: Wrong Answer

Solution code:
S = input()
for c in 'abcdefghijklmnopqrstuvwxyz':
    if c not in S:
        print(c)
        break
print('None')

Submission status: Wrong Answer

Solution code:
S = str(input())

tmp = "abcdefghijklmnopqrstuvwxyz"

for st in S:
    if(st in tmp):
        tmp = tmp.strip(st)

if tmp:
    print(tmp[0])
else:
    print("None")

Submission status: Wrong Answer

Solution code:
S = str(input())
tmp = "abcdefghijklmnopqrstuvwxyz"
for st in S:
    if(st in tmp):
        tmp = tmp.strip(st)
if tmp:
    print(tmp[0])
else:
    print("None")

Submission status: Wrong Answer

Solution code:
def not_found_minchar(S):
    su_S = sorted(set(S))
    idx = 0
    for o in range(ord('a'), ord('z') + 1):
        if idx < len(su_S) and o < ord(su_S[idx]):
            return chr(o)
        idx += 1
    return "None"

S = raw_input()
print not_found_minchar(S)

Submission status: Wrong Answer

Solution code:
s = input()
dup = set(s)
ans = ''

if   len(dup) == 26:
    print('None')
    exit()
else:
    chrs = sorted(dup)
    for i in range(97,122):
        if chr(i) not in chrs:
            ans = chr(i)
            break
print(ans)

Submission status: Wrong Answer

Solution code:
abc = sorted(list('qwertyuiopasdfghjklzxcvbnm'))
S = list(input())
for c in abc:
	if c not in S:
		print(c)
		quit()

Submission status: Wrong Answer

Solution code:
S = input()
S = set(S)
alp = [chr(ord('a') + i) for i in range(26)]
for i in alp:
  if i not in S:
    print(i)
    break

Submission status: Wrong Answer

Solution code:
import sys

s=list(input())
snum=len(list(set(s)))
if snum==26:
    print('None')
    sys.exit(0)
s.sort()
print(s[0])

Submission status: Wrong Answer

Solution code:
"""
a = "kanji"
for i in a:
  print(i)
"""

s = raw_input()
#print(s)

ch_lst = "abcdefghijklmnopqrstqvwxyz"
#ch_lst = [chr(i) for i in range(ord('a'), ord('z')+1)]
#print(ch_lst)

match = 0
for j in ch_lst:
  ch = s.find(j)
  if ch != -1:
    continue
  else:
    match = 1
    break

if match == 0:
  print("none")
elif match == 1:
  print(j)

Submission status: Wrong Answer

Solution code:
s=input()
array=[]
for i in range (len(s)):
    array.append(s[i])
for i in range(len(set(s))):
    if chr(97+i) in array:
        continue
    else:
        print(chr(97+i))
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
s=input()
array=[]
for i in range (len(s)):
    array.append(s[i])
for i in range(len(set(s))+1):
    if chr(97+i) in array:
        continue
    else:
        print(chr(97+i))
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
s=input()
array=[]
for i in range (len(s)):
    array.append(s[i])
for i in range(len(set(s))+1):
    if chr(97+i) in array:
        continue
    else:
        print(chr(97+i))
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
s=input()
array=[]
for i in range (len(s)):
    array.append(s[i])
for i in range(len(set(array))+1):
    if chr(97+i) in array:
        continue
    else:
        print(chr(97+i))
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
s=input()
array=[]
for i in range (len(s)):
    array.append(s[i])
for i in range(27):
    if chr(97+i) in array:
        continue
    else:
        print(chr(97+i))
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
s=input()
array=[]
for i in range (len(s)):
    array.append(s[i])
for i in range(len(set(s))):
    if chr(97+i) in array:
        continue
    else:
        print(chr(97+i))
        exit()
print("None")

Submission status: Wrong Answer

Solution code:
s=set(list(input()))
a=set(list('abcdefghijklmnopqrstuvwxyz'))

if s==a:
    print('None')
else:
    print(a-s)

Submission status: Wrong Answer

Solution code:
S=input()
for i in range(26):
    c = chr(i+97)
    if c not in S:
        print(c)
        exit()
print("none")

Submission status: Wrong Answer

Solution code:
S=input()
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=[c for c in S]
C=list(set(A)^set(B))
A=sorted(set(C),key=A.index)
if len(A)==0:
    print("none")
else:
    print(A[0])

Submission status: Wrong Answer

Solution code:
S=input()
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=[c for c in S]
C=list(set(A)^set(B))
D=sorted(set(C),key=A.index)
if len(D)==0:
    print("none")
else:
    print(D[0])

Submission status: Wrong Answer

Solution code:
S=input()
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=[c for c in S]
B.sort()
B=list(dict.fromkeys(B))
if len(B)==25 and B[-1]=="y":
    print("z")
elif len(B)==26:
    print("none")
else:
    for i in range(0,len(B)):
        if A[i] != B[i]:
            print(A[i])
            break

Submission status: Wrong Answer

Solution code:
S=input()
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=[c for c in S]
B.sort()
B=list(dict.fromkeys(B))
if len(B)==25 and B[-1]=="y":
    print("z")
elif len(B)==26:
    print("none")
else:
    for i in range(0,24):
        if A[i] != B[i]:
            print(A[i])
            break

Submission status: Wrong Answer

Solution code:
S=input()
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=[c for c in S]
B.sort()
B=list(dict.fromkeys(B))
for i in range(0,24):
    if A[i] != B[i]:
        print(A[i])
        break
if len(B)==25 and B[-1]=="y":
    print("z")
else:
    print("none")

Submission status: Wrong Answer

Solution code:
S=input()
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=[c for c in S]
B.sort()
for i in range(0,24):
    if A[i] != B[i]:
        print(A[i])
        break
else:
    print("none")

Submission status: Wrong Answer

Solution code:
S=input()
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=[c for c in S]
B.sort()
for i in range(0,24):
    if A[i] != B[i]:
        print(A[i])
        break
if len(B)<26:
        print("z")
else:
    print("none")

Submission status: Wrong Answer

Solution code:
alphabets = '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'.split()
s = sorted(list(set(input())))
N = len(s)
for i in range(N):
    if(s[i] != alphabets[i]):
        print(alphabets[i])
        break
    if(i == 25):
        print('None')

Submission status: Wrong Answer

Solution code:
alphabets = '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'.split()
s = sorted(list(set(input())))
N = len(s)
for i in range(N):
    if(s[i] != alphabets[i]):
        print(alphabets[i])
        break
    if(i == N-1):
        print('None')

Submission status: Wrong Answer

Solution code:
a=list(input())
b=[chr(i) for i in range(97, 97+26)]
for x in b:
  if not x in a:
     print(x)
     break

Submission status: Wrong Answer

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

Submission status: Wrong Answer

Solution code:
S = input()
alphbet = 'abcdefghijklmnopqrstuvwxyz'

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

Submission status: Wrong Answer

Solution code:
N=[chr(i) for i in range(97,123)]
s=sorted(set(list(input())))
for i in s:
    if i not in N:
        print(i)
        break
else:
    print("None")

Submission status: Wrong Answer

Solution code:
# input
S = input()

alphabet = ['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', 'None']

for i in range(len(alphabet)):
    if alphabet[i] in S:
        continue
    else:
        print(alphabet[i])

Submission status: Wrong Answer

Solution code:
S = list(input())
a = list("abcdefghijklmnopqrstuvwxyz")
a.append("None")
i = 0
for c in S:
    if c == a[i]:
        i += 1

print(a[i])

Submission status: Wrong Answer

Solution code:
S = input()
S_list = list(set(S))
al = 'abcdefghijklmnopqrstucwxyz'
al_list = list(al)
S_list.sort()

for i in range(len(set(S))):
    if al_list[i] in S_list:
        pass
    else:
        print(al_list[i])
        break
    
if i == len(set(S)) - 1:
    print('None')

Submission status: Wrong Answer

Solution code:
S = input()
S_list = list(set(S))
al = 'abcdefghijklmnopqrstucwxyz'
al_list = list(al)
S_list.sort()

for i in range(len(set(S))):
    if al_list[i] in S_list:
        pass
    else:
        print(al_list[i])
        break
    
if i == len(set(S)) - 1:
    print('None')

Submission status: Wrong Answer

Solution code:
S = sorted(list(set(list(input()))))
alph = "abcdefghijklmnopqrstuvwxyz"

ans = []
for i in S:
    if i not in S:
        ans.append(i)
if not ans:
    print("None")
else:
    print(ans[0])

Submission status: Wrong Answer

Solution code:
S = input()

alphabets=["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 alphabet in alphabets:
    flag = 1
    for character in S:
        if character == alphabet:
            flag = 0
    if flag == 1:
        print(alphabet)
        break

Submission status: Wrong Answer

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

if len(set(s)) == 26:
    print("None")
else:
    alp = [chr(i) for i in range(97, 97+26)]
    print(alp)
    for a in alp:
        if a not in sorted(set(s)):
            print(a)
            break

Submission status: Wrong Answer

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

if len(s) == 26:
    print("None")
else:
    alp = [chr(i) for i in range(97, 97+26)]

    for a in alp:
        if a not in sorted(s):
            print(a)
            break

Submission status: Wrong Answer

Solution code:
s = input()
alp = "abcdefghijklmnopqrstuvwxyz"

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

Submission status: Wrong Answer

Solution code:
s = input()
alp = "abcdefghijklmnopqrstuvwxyz"

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

Submission status: Wrong Answer

Solution code:
s = input()
alp = "abcdefghijklmnopqrstuvwxyz"
al = alp.strip(s[0])
for i in range(len(s)-1):
    al = al.strip(s[i+1])
if al != "":
    print(al[0])
else:
    print("None")

Submission status: Wrong Answer

Solution code:
al = "abcdefghijklmnopqrstuvwxyz"
S1 = list(set(sorted(input())))
if (len(S1)==26):
    print("None")
else:
    for i in range (len(S1)):
        if al[i] != S1[i]:
            print(al[i])
            break
    print(al[len(S1)])

Submission status: Wrong Answer

Solution code:
al = "abcdefghijklmnopqrstuvwxyz"
S1 = set(sorted(input()))
if (len(al)==26):
    print("None")
else:
    for i in range (len(S1)):
        if al[i] != S1[i]:
            print(al[i])
            break

Submission status: Wrong Answer

Solution code:
s=input()
a='abcdefghjklmnopqrstuvwxyz'
for i in s:
    a=a.replace(i,'')
if len(a)!=0: print(a[0])
else: print('None')

Submission status: Wrong Answer

Solution code:
from collections import Counter
import string

S = input()
count = Counter(list(S))

for ch in string.ascii_lowercase:
    if count[ch] == 0:
        print(ch)
        break

Submission status: Wrong Answer

Solution code:
data=input()
temp=[chr(97+i) for i in range(26)]
for i in range(len(data)):
    temp[ord(data[i])-97]=0
cnt=26
for i in range(26):
    if temp[i]!=0:
        cnt=i
        break
if cnt<=25:print(temp[cnt])
else:print("NULL")

Submission status: Wrong Answer

Solution code:
S=sorted(list(set(list(input()))))
alph=["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"]
sum=0
A="None"
for i in range(len(S)):
    if S[i]!=alph[i]:
        A=alph[i]
        break
print(A)

Submission status: Wrong Answer

Solution code:
S=sorted(list(set(list(input()))))
alph=["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"]
sum=0
for i in range(len(S)):
    sum+=1
    if S[i]!=alph[i]:
        print(alph[i])
        break
if sum==26:
    print("None")

Submission status: Wrong Answer

Solution code:
S=sorted(list(set(list(input()))))
alph=["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(S)):
    if len(S)==26:
        print("None")
        break
    elif S[i]!=alph[i]:
        print(alph[i])
        break

Submission status: Wrong Answer

Solution code:
S=sorted(list(set(list(input()))))
alph=["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(S)):
    if len(S)==26:
        print("None")
        break
    if S[i]!=alph[i]:
        print(alph[i])
        break

Submission status: Wrong Answer

Solution code:
S=sorted(list(set(list(input()))))
if len(S)==26:
    print("None")
alph=["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(S)):
    if S[i]!=alph[i]:
        print(alph[i])
        break

Submission status: Wrong Answer

Solution code:
S=set(input())
Sl=list(S)
Sl.sort()
moji=["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"]
T="None"
for i in range(len(Sl)):
    if Sl[i]!=moji[i]:
        T=moji[i]
        break

print(T)

Submission status: Wrong Answer

Solution code:
s = list(input())
s = list(set(s))
s.sort()
t = [chr(i) for i in range(97, 97+26)]

cnt = 0
for i in range(len(s)):
   if s[i] != t[i]:
      print(t[i])
      break
   cnt += 1

if cnt == len(s):
   print("None")

Submission status: Wrong Answer

Solution code:
s = list(input())
s = list(set(s))
s.sort()
t = [chr(i) for i in range(97, 97+26)]
print(s)
print(t)

cnt = 0
for i in range(len(s)):
   if s[i] != t[i]:
      print(t[i])
      break
   cnt += 1

if cnt == len(s):
   print("None")

Submission status: Wrong Answer

Solution code:
s = list(input())
s = list(set(s))
s.sort()
t = [chr(i) for i in range(97, 97+26)]

cnt = 0
for i in range(len(s)):
   cnt += 1
   if s[i] != t[i]:
      print(t[i])
      break

if cnt == len(t):
   print("None")

Submission status: Wrong Answer

Solution code:
s = list(input())
s = list(set(s))
s.sort()
t = [chr(i) for i in range(97, 97+26)]

cnt = 0
for i in range(len(s)):
   cnt += 1
   if s[i] != t[i]:
      print(t[i])
      break

if cnt == len(s):
   print("None")

Submission status: Wrong Answer

Solution code:
ans = "abcdefghijklmnopqrstuvwxyz"
for c in input():
    ans.replace(c, '')
if len(ans) == 0:
    print("None")
else:
    ans[0]

Submission status: Wrong Answer

Solution code:
s=set(input())
for c in list("abcdefghijklmnopqrstuvwxyz"):
    if c not in s:
        print(c)
        break

Submission status: Wrong Answer

Solution code:
s=input()
print(s)
for i in range(97,97+26):
    if chr(i) not in s:
        print(chr(i))
        exit()
print('None')

Submission status: Wrong Answer

Solution code:
s=input()
print(s)
for i in range(97,97+26):
    if chr(i) not in s:
        exit()
print('None')