/in/foo.cc: In function 'int main()':
/in/foo.cc:8:17: warning: array subscript has type 'char' [-Wchar-subscripts]
    8 |         while(s[i]){
      |                 ^
/in/foo.cc:9:19: warning: array subscript has type 'char' [-Wchar-subscripts]
    9 |                 s[i]-=k;
      |                   ^
/in/foo.cc:10:22: warning: array subscript has type 'char' [-Wchar-subscripts]
   10 |                 if(s[i]<'A')s[i]+=26;
      |                      ^
/in/foo.cc:10:31: warning: array subscript has type 'char' [-Wchar-subscripts]
   10 |                 if(s[i]<'A')s[i]+=26;
      |                               ^
/in/foo.cc:11:22: warning: array subscript has type 'char' [-Wchar-subscripts]
   11 |                 if(s[i]>'Z')s[i]-=26;
      |                      ^
/in/foo.cc:11:31: warning: array subscript has type 'char' [-Wchar-subscripts]
   11 |                 if(s[i]>'Z')s[i]-=26;
      |                               ^