백준 1157 단어 공부

https://www.acmicpc.net/problem/1157

1157번: 단어 공부

alpha = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
inp = input()
cnt = []
for i in range(26):
    cnt.append(inp.count(alpha[i])+inp.count(chr(ord(alpha[i])+32)))
mx = max(cnt)
mi = cnt.index(mx)
cnt[cnt.index(mx)] = 0
result = 0
for i in range(26):
    if cnt[i] == mx:
        result = 1
        break
if result == 1:
    print('?')
else:
    print(alpha[mi])