/in/foo.cc: In function 'int main()':
/in/foo.cc:11:26: warning: array subscript has type 'char' [-Wchar-subscripts]
   11 |         for(char &j:s)ch[j]++;
      |                          ^
/in/foo.cc:12:52: warning: array subscript has type 'char' [-Wchar-subscripts]
   12 |         for(char j='a';j<='z';j++)minn=min(minn,ch[j]);
      |                                                    ^