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: Runtime Error

Solution code:
s = sorted(set(input()))
for i in range(26):
    if s[i] != chr(97+i):
        print(chr(97+i))
        break
else:
    print('None')

Submission status: Runtime Error

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()
j = 97
ok = 0
for i in range(L):
    if Slist[i] == j:
        j += 1
        continue
    ans = chr(j)
    ok = 1
    break
if len(Slist) == 26:
    ans = "None"
elif ok == 0:
    ans = chr(j)
print(ans)

Submission status: Runtime Error

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
for i in range(97, 123):
    if Slist[j] == i:
        j += 1
        continue
    ans = chr(i)
    break
print(ans)

Submission status: Runtime Error

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

Submission status: Runtime Error

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

Submission status: Runtime Error

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

s.sort()

for i in range(26):
    if s[i] != chr(i + ord('a')):
        print(chr(i + ord('a')))
        exit()
else:
    print('None')

Submission status: Runtime Error

Solution code:
s = list(input())
t = [chr(i) for i in range(ord("a"), ord("z") + 1)]
for i in s:
  t.remove(i)
if t:
  print(t[0])
else:
  print("None")

Submission status: Runtime Error

Solution code:
s = list(input())
t = [chr(i) for i in range(ord("a"), ord("z") + 1)]
for i in s:
  t.remove(i)
print(t[0])

Submission status: Runtime Error

Solution code:
s=input()
l='abcdefghijklmnopqrstuvwxyz'
s=''.join(list(set(s)))
s=sorted(s)
f=0
for i in range(26):
    if(s[i]!=l[i]):
        print(l[i])
        f=1
        break
if(f==0):
    print('None')

Submission status: Runtime Error

Solution code:
s=input()
l='abcdefghijklmnopqrstuvwxyz'
s=''.join(list(set(s)))
s=sorted(s)
for i in range(26):
    if(s[i]!=l[i]):
        print(l[i])
        exit()

Submission status: Runtime Error

Solution code:
s = input()

import string
a = list(string.ascii_lowercase)

for item in a:
    if item not in s:
        print(a[i])
        break
else:
    print('None')

Submission status: Runtime Error

Solution code:
alphabeta = "abcdefghijklmnopqrstuvwxyz"
all_str  = set(alphabeta) 
str = input() 
str = set(str)
use = all_str-str 
print(sorted(use)[0])

Submission status: Runtime Error

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(26):
  if L[i]!=R[i]:
    print(R[i])
    exit()
print("None")

Submission status: Runtime Error

Solution code:
S = set(input())
a = set([chr(i) for i in range(ord('a'), ord('z')+1)])
print(sorted(list(a-S))[0])

Submission status: Runtime Error

Solution code:
s = list(input())
s = list(set(s))
s.sort()
if len(s) == 26:
    print("None")
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 range(26):
    if s[i] != l[i]:
        print(l[i])
        break

Submission status: Runtime Error

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

Submission status: Runtime Error

Solution code:
al = list("abcdefghijklmnopqrstuvwxyz")

s = list(input())
for i in s:
    if i in al:
        del al[al.index(i)]
        
if len(s) == 0:
    print("None")
else:
    print(al[0])

Submission status: Runtime Error

Solution code:
S=input()
x="None"
num=[False for i in range(26)]
for i in range(len(S)):
    num[ord(S[i])-ord("a")]=True

for j in range(26):
    if !num[j]:
        x=chr(j+ord("a"))
        break

print(x)

Submission status: Runtime Error

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']

for i in S:
    if i in a:
        a.remove(i)
#print(a)
print(a[0])

Submission status: Runtime Error

Solution code:
s_list = list(input())
 
result = None
 
for s_uni in range(ord('a'), ord('z') + 1):
    if not chr(s_uni) in s_list:
        result = chr(s_uni)
        break
 
if result:
  print(result)
else
  print('None')

Submission status: Runtime Error

Solution code:
s_list = list(input())

small = None

for s_uni in range(ord('a'), ord('z') + 1):
    if not chr(s_uni) in s_list:
        small = chr(s_uni)
        break

if small:
  print(smal)
else
  print('None')

Submission status: Runtime Error

Solution code:
import sys
from string import ascii_lowercase as aplhabets
from collections import defaultdict

readline=sys.stdin.readline

s=readline().split()
d=defautdict(int)
for x in s:
  d[x]=1
for a in alphabets:
  if d[a]==0:
    print(a)
    sys.exit()
print('None')

Submission status: Runtime Error

Solution code:
import sys
from string import ascii_lowercase as aplhabets
from collections import defaultdict

readline=sys.stdin.readline

s=readline().split()
d=defautdict(int)
for x in s:
  d[x]=1
for a in alphabets:
  if d[a]=0:
    print(a)
    sys.exit()
print('None')

Submission status: Runtime Error

Solution code:
S = list(input())
S.sort()
import bisect
a_uni = ord('a')

Search = S
for i in range(26):
    char = chr(a_uni+i)
    if Search[0] == char:
        ind = bisect.bisect_right(S,char)
        Search = S[ind:]
        continue
    print(char)
    exit()
print('None')

Submission status: Runtime Error

Solution code:
S = input()
List = list(S)
s_l = set(List)
n = 10
res= ""
for i in range(97,113):
  n = s_l.count(chr(i))
  if n == 0:
    res = chr(i)
    break
print(res)

Submission status: Runtime Error

Solution code:
S = list(input())
USED = [False] * 26

for s in S:
  USED[ord(s)-96] = True
  
ok = False
ans = None
for i in range(26):
  if not USED[i]:
    ans = chr(96+i)
    ok = True
    break
    
if ok:
  print(ans)
else:
  print("None")

Submission status: Runtime Error

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)))
    break

Submission status: Runtime Error

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)]
if ans==all:
  print('None')
  exit()
for i in range(len(ans)):
  if ans[i]!=all[i]:
    print(all[i])
    exit()
  else:
    print(all[len(ans)])
    exit()

Submission status: Runtime Error

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(27):
  if ans[i]!=all[i]:
    print(all[i])
    exit()
print('None')

Submission status: Runtime Error

Solution code:
import string
s = str(input())
low = string.ascii_lowercase
fin = ''
for i in range(len(low)):
    if low[i] not in s:
        fin += low[i]
        
print(fin[0])

Submission status: Runtime Error

Solution code:
S = list(input())
lst = [chr(i) for i in range(97, 97+26)]
res = sorted(list(set(lst) - set(S)))

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

Submission status: Runtime Error

Solution code:
s=input()
alh="abcdefghijklmnopqrstuvwxyz"
exist=False
ans="None"
for i in alf:
  if i in s:
    exist=True
  if not exist:
    ans=i
    break
print(ans)

Submission status: Runtime Error

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

Submission status: Runtime Error

Solution code:
arb = 'abcdefghijklmnopqrstuvwxyz'
S = input()
s_S =sorted(set(arb)^set(S))
print(s_S[0])

Submission status: Runtime Error

Solution code:
import sys
s = list(input())
for i in range(0,26):
  if not chr(97+i) in s:
    print(chr+i)
    sys.exit()
print("None")

Submission status: Runtime Error

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.trplace(s[i],"")
print(alf)
if alf == "":
	print("None")
else:
	print(alf[0])

Submission status: Runtime Error

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])

Submission status: Runtime Error

Solution code:
#include <bits/stdc++.h>
using namespace std;
  
int main() {
  string S;
  cin >> S;
  
  int bucket[26]={0};//バケット
  
  for(int i=0;i<S.length();i++){
    int tmp= S.at(i)-'a';
    bucket[tmp]++;
  }
  
  int ans=-1;//答えを格納
  for(int i=0; i<26; i++){
    if (bucket[i]==0){
      ans=i;
      break;
    }
  }
  
  if(ans==-1){
    cout << "None" << endl;
  }else{
    printf("%c\n",ans+97);
  }
  
  return 0;
      
}

Submission status: Runtime Error

Solution code:
#include <bits/stdc++.h>
using namespace std;
  
int main() {
  string S;
  cin >> S;
  
  int bucket[26]={0};//バケット
  
  for(int i=0;i<S.length();i++){
    int tmp= S.at(i)-'a';
    bucket[tmp]++;
  }
  
  int ans=-1;//答えを格納
  for(int i=0; i<26; i++){
    if (bucket[i]==0){
      ans=i;
      break;
    }
  }
  
  if(ans==-1){
    cout << "None" << endl;
  }else{
    printf("%c\n",ans+97);
  }
      
}

Submission status: Runtime Error

Solution code:
s = str(input())
a = "abcdefghijklmnopqrstuvwxyz"
count = 0
n = 0
for i in range(len(a)):
    for j in range(len(s)):
        if a[i] == s[j]:
            count += 1
            break
    if count == 0:
        ans = a[i]
        print(ans)
        n = 1
        break
    else:
        count = 0
if n = 1:
    print("None")

Submission status: Runtime Error

Solution code:
s = str(input())
a = "abcdefghijklmnopqrstuvwxyz"
count = 0
for i in range(len(a)):
    for j in range(len(s)):
        if a[i] == s[j]:
            count += 1
    if count == 0:
        ans = a[i]
        break
    else:
        count = 0
print(ans)

Submission status: Runtime Error

Solution code:
import string
S=sorted(set((input())))
count = 0
for i in string.ascii_lowercase:
  if i!=S[count]:
    print(i)
    break
  count += 1
else:
  print('None')

Submission status: Runtime Error

Solution code:
a=sorted(set(input())^set(map(chr(range(97,123)))));print(a and a[0]or None)

Submission status: Runtime Error

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

for i in range(len(m)):
    if s[i] != m[i]:
        print(m[i])
        exit(0)

print('None')

Submission status: Runtime Error

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

for i in range(26):
    if s[i] != m[i]:
        print(m[i])
        exit(0)

print('None')

Submission status: Runtime Error

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

for i in range(26):
    if s[i] != m[i]:
        print(s[0])
        exit(0)

print('None')

Submission status: Runtime Error

Solution code:
#!/usr/bin/env python
# coding: utf-8

# In[18]:


S = input()


# In[19]:


mylist = list(sorted(set(S)))
abc = "abcdefghijklmnopqrstuvwxyz"
for i in range(len(abc)):
    if mylist[i] != abc[i]:
        print(abc[i])
        break
else:
    print("None")


# In[ ]:

Submission status: Runtime Error

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 = list(s())
s = list(set(s))
s.sort()
ans = [str (i) for i in "abcdefghijklmnopqrstuvwxyz"]
#print("s",s)
#print("ans",ans)
#print(len(s))
for i in range(len(s)):
	#print("s",i)
	#print("ans",s)
	#print(ans)
	print(s[i])
	if s[i] in ans: #s[i] in ans なら
		ans.pop(i-1)
		print(i,"ans",ans)
print(ans[0])

Submission status: Runtime Error

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 i in l:
    if not i in s:
        print(i)
        break

Submission status: Runtime Error

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 i in l:
    if not i in s:
        print(i)
        break

Submission status: Runtime Error

Solution code:
S = input()

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

remain = list(set(alpha) - set(S))
remain.sort()
print(remain[0])

Submission status: Runtime Error

Solution code:
s = list(input())
s2 = []
for i in range(len(s)):
    s2.append(s[i])
s3 = list(set(s2))
s3.sort()
s4 = ['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 s3 == s4:
    print('None')
else:
    for i in range(int(len(s4))):
        if s3[i] != s4[i]:
            print(s4[i])
            break

Submission status: Runtime Error

Solution code:
s = list(input())
s2 = []
for i in range(len(s)):
    s2.append(s[i])
s2 = list(set(s2))
s2.sort()
s3 = ['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 s2 == s3:
    print('None')
else:
    for i in range(int(len(s3))):
        if s2[i] != s3[i]:
            print(s3[i])
            break

Submission status: Runtime Error

Solution code:
s = input()
s2 = []
for i in range(len(s)):
    s2.append(s[i])
s2 = list(set(s2))
s2.sort()
s3 = ['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 s2 == s3:
    print('None')
else:
    for i in range(int(len(s3))):
        if s2[i] != s3[i]:
            print(s3[i])
            break

Submission status: Runtime Error

Solution code:
s = input()
s2 = []
for i in range(len(s)):
    s2.append(s[i])
s2 = list(set(s2))
s2.sort()
s3 = ['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 s2 == s3:
    print('None')
else:
    for i in range(len(s3)):
        if s2[i] != s3[i]:
            print(s3[i])
            break

Submission status: Runtime Error

Solution code:
s = input()
s2 = []
for i in range(len(s)):
    s2.append(s[i])
s2 = list(set(s2))
s2.sort()
s3 = ['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 s2 == s3:
    print('None')
else:
    for i in range(len(s)):
        if s2[i] != s3[i]:
            print(s3[i])
            break

Submission status: Runtime Error

Solution code:
s = input()
alpha = abcdefghijklmnopqrstuvwxyz

for i in list(alpha):
  if i not in s:
    print(i)
    exit()
    
print('None')

Submission status: Runtime Error

Solution code:
s = sorted(set(input()))
if len(s) ==26:
    print("None")
else:
    for i,k in enumerate("abcdefghijklmnopqrstuvwxyz"):
        if k != s[i]:
            print(k)
            break

Submission status: Runtime Error

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

Submission status: Runtime Error

Solution code:
n, m = map(int, input().split())

num = set(list(range(1, m + 1)))
for i in range(n):
    in_li = list(map(int, input().split()))
    num = num & set(in_li[1:])
print(len(num))

Submission status: Runtime Error

Solution code:
S = input()

al_list = [chr(i) for i in range(97, 97+26)]
s_list = []
Flag = True

for al in S:
    s_list.append(al)

if s_list == al_list:
    print('None')
else:
    print(min(list(set(al_list) - set(s_list))))

Submission status: Runtime Error

Solution code:
S = input()

for i in range(97,26+97):
    if chr(i) not in s:
        print(chr(i))
        exit(0)
else:
    print('None')

Submission status: Runtime Error

Solution code:
s = input()
ll = [i for i in range(97,123,1)]
for j in s:
    s_num = ord(j)
    if s_num in ll:
        ll.remove(s_num)
    else:
        pass
print(chr(ll[0]))

Submission status: Runtime Error

Solution code:
S=list(input())
l=sorted(list(set(S)))
for i in range(97,97+26):
    if chr(i) !=l.pop(0):
        print(chr(i))
        break
    elif chr(i) == 'z':
        print('None')

Submission status: Runtime Error

Solution code:
S=list(input())
l=sorted(list(set(S)))
for i in range(97,97+26):
    if chr(i) !=l.pop(0):
        print(chr(i))
        break

Submission status: Runtime Error

Solution code:
import sys
S=input()
s=[]
for i in S:
    s.append(i)
x=[chr(i) for i in range(97,97+26)]
s.sort()
l=sorted(set(s),key=s.index)
for i in range(len(x)):
    if l[i]!=x[i]:
        print(x[i])
        sys.exit()
print("None")

Submission status: Runtime Error

Solution code:
S = list(input())
S = set(S)
for i in range(26):
  if not(chr(97+i) in S):
    ans = chr(97+i)
    break
print(ans)

Submission status: Runtime Error

Solution code:
S = input()
S = sorted(set(S))
A = "abcdefghijklmnopqrstuvwxyz"
for i in range(len(A)):
  if len(A) == len(S):
    print("None")
    break
  if A[i] != S[i]:
    print(A[i])
    break
  if i == len(S):
    print(A[i + 1])
    break

Submission status: Runtime Error

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

Submission status: Runtime Error

Solution code:
S = list(input())
s = sorted(list(set(S)))
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']

ans = 'None'

for i in range(26):
    if s[i] != l[i]:
        ans = l[i]
        break

print(ans)

Submission status: Runtime Error

Solution code:
n=input()
l=sorted(n)
li=list(set(l))
li.sort()
la=[chr(ord('a') + i) for i in range(26)]
ans=""
for i in range(26):
    if li[i]!=la[i]:
        ans=la[i]
        break
    else:
        pass

if ans=="":
  print("None")
else:
  print(ans)

Submission status: Runtime Error

Solution code:
S = list(input())
All = list("abcdefghijklmnopqrstuvwxyz")
res = list(set(S) ^ set(All))
print(res[0])

Submission status: Runtime Error

Solution code:
S = set(input())

li = list({chr(ord('a') + i) for i in range(26)} - S)
li = sorted(li)

print(li[0])

Submission status: Runtime Error

Solution code:
import sys
import string

input = sys.stdin.readline

def main():
    ans = 'None'
    S = list(set(input()))
    s = list(string.ascii_lowercase)
    for i in S:
        s.remove(i)
    if s:
        ans = s[0]
    print(ans)

if __name__ == '__main__':
    main()

Submission status: Runtime Error

Solution code:
import sys
import string

input = sys.stdin.readline

def main():
    ans = 'None'
    S = set(input())
    s = list(string.ascii_lowercase)
    for i in S:
        s.remove(i)
    if s:
        ans = s[0]
    print(ans)

if __name__ == '__main__':
    main()

Submission status: Runtime Error

Solution code:
s = input()
alpha = 'abcdefghijklmnopqrstuvwxyz'
for i in s:
  if i in alpha:
    alpha = alpha.strip(i)

print(alpha[0])

Submission status: Runtime Error

Solution code:
import sys
S = sorted(set(input()))

alp = ['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(alp)):
  if S[i] != alp[i]:
    print(alp[i])
    sys.exit()

print('None')

Submission status: Runtime Error

Solution code:
s = set(list("abcdefghijklmnopqrstuvwxyz"))-set(list(input()))
if len(s)==0:
  print("None")
else:
  print(s[0])

Submission status: Runtime Error

Solution code:
def resolve():
    # 整数 1 つ
    s = input()
    # 整数複数個
    # a, b, c = list(map(int, input().split()))
    # 整数 N 個 (改行区切り)
    # N = [int(input()) for i in range(N)]
    # 整数 N 個 (スペース区切り)
    # N = list(map(int, input().split()))
    # 整数 (縦 H 横 W の行列)
    # A = [list(map(int, input().split())) for i in range(H)]

    alpha = string.ascii_lowercase
    A = [alpha[i] for i in range(len(alpha))]

    for x in A:
        if x not in s:
            print(x)
            break
        if x == "z":
            print("None")

resolve()

Submission status: Runtime Error

Solution code:
s = input()
g1 = set("abcdefghijklmnopqrstuvwxyz")
g2 = set(s)
a = g1 -g2
print(sorted(list(a))[0])

Submission status: Runtime Error

Solution code:
S = list(input())
S = sorted(S)
num = len(set(S))
newS = sorted(list(set(S)))

if num == 26:
    print('None')
else:
    for i in range(26):
        if newS[i] != chr(i+97):
            print(chr(i+97))
            break

Submission status: Runtime Error

Solution code:
import string

S = list(map(str, input()))
s = sorted(set(S))

alphabet = string.ascii_lowercase

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

else:
    for i in range(30):
        if s[i] != alphabet[i]:
            print(alphabet[i])
            break

Submission status: Runtime Error

Solution code:
import string

S = list(map(str, input()))

s = sorted(set(S))

alphabet = string.ascii_lowercase

if len(s) == len(alphabet):
    print("None")
else:

    for i in range(53):
        if s[i] != alphabet[i]:
            print(alphabet[i])
            break

Submission status: Runtime Error

Solution code:
import numpy as np
import sys

input = sys.stdin.readline

S = input()

S = sorted(S[:-1])

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']


s = 0
for t in S:
    if t == alpha[s] :
        s+=1


if s == len(alpha):
    print("None")
else:
    print(alpha[s])

Submission status: Runtime Error

Solution code:
import numpy as np
S=input()
a_list = "abcdefghijklmnopqrstuvwxyz"
c_list = np.zeros(26)

for i in range(len(S)):
  c_list[a_list.index(S[i])] = c_list[a_list.index(S[i])] + 1

if not 0 in c_list: print('None')
else:
  print(a_list[c_list.index(0)])

Submission status: Runtime Error

Solution code:
s=str(input())
al=[]
for i in range(97,123):
  al.append(chr(i))
for j in range(len(s)):
  if s[j] in al:
    al.remove(s[j])
    print(min(al))
if al==[]:
  print('None')
  exit()

Submission status: Runtime Error

Solution code:
s=str(input())
al=[]
for i in range(97,123):
  al.append(chr(i))
for j in range(len(s)):
  if s[j] in al:
    al.remove(s[j])
    print(min(al))
  if al==[]:
    print('None')
    exit()

Submission status: Runtime Error

Solution code:
Sold = list(map(str, input()))
Snew = set(S)
alph = set(list('abcdefghijklmnopqrstuvwxyz'))
if len(list(Snew-alph))==0:
  print('none')
else:
  print(sorted(list(Snew-alph))[0])

Submission status: Runtime Error

Solution code:
Sold = list(map(str, input()))
Snew = list(set(S))
alfa = [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 Snew[i] != alfa[i]:
    print(alfa[i])
    exit()
print('None')

Submission status: Runtime Error

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

Submission status: Runtime Error

Solution code:
S = input()
list = []
for i in range(len(S)):
    list.append(S[i])
list = set(list)
lists = set([chr(i) for i in range(ord('a'), ord('z')+1)])
print(min(lists-list))

Submission status: Runtime Error

Solution code:
S=str(input())
list_ = "abcdefghijklmnopqrstuvwxyz"
for i in range(len(S)):
  if len([1 for s in list_ if s==S[i]])>0:
    n=list_.index(S[i])
    list_ = list_[:n] + list_[n + 1:]
print(list_[0])

Submission status: Runtime Error

Solution code:
S=str(input())
list_ = "abcdefghijklmnopqrstuvwxyz"
for i in range(len(S)):
  if len([1 for s in list_ if s==S[i]]>0):
    n=list_.index(S[i])
    list_ = list_[:n] + list_[n + 1:]
print(list_[0])

Submission status: Runtime Error

Solution code:
S=input()
K='abcdefghijklmnopqrstuvwxyz'
ans=True
for i in range(len(S)):
    if K[i] in S:
        continue
    else:
        ans=False
        break
print(K[i] if ans==False else 'None')

Submission status: Runtime Error

Solution code:
S=input()
K='abcdefghijklmnopqrstuvwxyz'
for i in range(len(S)):
    if K[i] in S:
        continue
    else:
        print(K[i])
        break

Submission status: Runtime Error

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

for c in t:
  if t in s:
    cotinue
  else:
    print(c)
    exit()

Submission status: Runtime Error

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

Submission status: Runtime Error

Solution code:
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int main() {
    string S;
    cin >> S;
    vector<bool> app(26, false);

    for (char c : S) {
        app.at(c - 'a') = true;
    }

    rep (i, 26) {
        if (!app.at(i)) {
            cout << (char)(i + 'a') << endl;
            return 0;
        }
    }

    cout << "None" << endl;
}

Submission status: Runtime Error

Solution code:
s = input()
l = sorted(list({s[i] for i in range(len(s))}))
if len(l) == 26:
    ans = "None"
else:
    for i in range(len(l) - 1):
        if ord(l[i]) + 1 != ord(l[i + 1]):
            ans = chr(ord(l[i]) + 1)
            break
print(ans)

Submission status: Runtime Error

Solution code:
s = input()
alps = 'abcdefghijklmnopqrstuvwxyz'
for i in alps:
    if i not in s:
        print(alp)
        break
else:
    print('None')

Submission status: Runtime Error

Solution code:
s=sorted(set(input()))
ro='abcdefghijklmnopqrstuvwxyz'
if len(s)==len(ro):
    print('None')
else:
    for i in range(len(ro)):
        if s[i]!=ro[i]:
            print(ro[i])
            break

Submission status: Runtime Error

Solution code:
a=int(input())
b=1
for i in range(7):
    if a>=i**2:
        b=i**2
print(b)

Submission status: Runtime Error

Solution code:
a=int(input())
b=1
for i in range(7):
    if a>=i**2:
        b+=i**2
print(b)

Submission status: Runtime Error

Solution code:
a=int(input())
b=1
for i in range(7):
    if a>=i**2:
        b =i**2
print(b)

Submission status: Runtime Error

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

Submission status: Runtime Error

Solution code:
import string

s = set(input())

a = set(string.ascii_lowercase)
b = a - c
ans = b[0] if len(b) else "None"
print(ans)

Submission status: Runtime Error

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

Submission status: Runtime Error

Solution code:
import string
s = list(set(list(input())))
s.sort()
comp = string.ascii_lowercase
if len(s) == len(comp):
    ans = 'None'
else:
    for i, j in zip(s, string.ascii_lowercase):
        if i != j:
            ans = j
            break
print(ans)

Submission status: Runtime Error

Solution code:
import sys
s = list(set(input()))
s.sort()
alp = list('abcdefghijklmnopqrstuvwxyz')
count=0
#if s include all alp, print None and exit 
if len(s) == 25:
    print('None')
    sys.exit()

for s_,alp_ in zip(s,alp):
    count += 1  
    if s_ != alp_ :
        print(alp_)
        sys.exit()
    
print(alp[count])

Submission status: Runtime Error

Solution code:
import sys
s = list(set(input()))
s.sort()
alp = list('abcdefghijklmnopqrstuvwxyz')

count = 0
for s_,alp_ in zip(s,alp):
    if s_ != alp_ :
        print(alp_)
        sys.exit()
    count += 1

print('None' if count == 24 else alp[count])

Submission status: Runtime Error

Solution code:
import sys
s = list(set(input()))
s.sort()
alp = list('abcdefghijklmnopqrstuvwxyz')

count = 0
for s_,alp_ in zip(s,alp):
    if s_ != alp_ :
        print(alp_)
        sys.exit()
    count += 1

print('None' if count == 25 else alp[count])

Submission status: Runtime Error

Solution code:
alphabet = [chr(ord('a') + i) for i in range(26)]
s = list(input())
s = list(set(s))
s.sort()
for i in range(len(s)):
    if i == len(s) - 1:
        print(alphabet[i + 1])
        exit()
    elif s[i] == alphabet[i]:
        pass
    else:
        print(alphabet[i])
        exit()
print("None")

Submission status: Runtime Error

Solution code:
s=input()

sets=set(s)

for i in range(97,123):
  if not ord(i) in sets:
    print(ord(i))
    exit()
print("None")

Submission status: Runtime Error

Solution code:
s=input()
a=[chr(i) for i in range(ord("a"),ord("z")+1) if i not in s]
print("None" if len(a)==0 else a[0])

Submission status: Runtime Error

Solution code:
S=set(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"}
D=sorted(list(A-S))
print(D[0])

Submission status: Runtime Error

Solution code:
s = set(input())
alp = "abcdefghijklmnopqrstuvwxyz"
alpl = [i for i in alp]
for i in s:
    if i in alp:
        alpl.remove(i)
        
print(sorted(alpl)[0])

Submission status: Runtime Error

Solution code:
import string

s = set(input())

abc = set(string.ascii_lowercase)
rest = abc - s

print(min(rest))

Submission status: Runtime Error

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

s = input()
s_li = set(sorted(list(s)))

for v in alph:
    if v not in s_li:
        print(v)
        exit(0)
print('None')

Submission status: Runtime Error

Solution code:
s=set(input())
a=[]
for i in s:
  a.append(ord(i)-ord("a"))
for i in range(26):
  if i not in a:
    print(chr(i+ord("a"))
    break

Submission status: Runtime Error

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

Submission status: Runtime Error

Solution code:
s = set(list(input()))
b = set(list("abcdefghijklmnopqrstuvwxyz"))

print(sorted(list(b-s))[0])

Submission status: Runtime Error

Solution code:
S=input()
al=[chr(ord('a') + i) for i in range(26)]
ss=set(al)

for str in S:
  if str in ss:
    ss.remove(str)

print(sorted(ss)[0])

Submission status: Runtime Error

Solution code:
S=sorted(set(input()))
ans=None
for i in range(97,97+26):
  if chr(i)!=S[i-97]:
    ans=chr(i)
    break
print(ans)