/in/foo.cc: In function 'int main()':
/in/foo.cc:9:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0;i<s.size();i++) cout << char(s[i]+3);
               ~^~~~~~~~~
/in/foo.cc:7:7: warning: unused variable 'ans' [-Wunused-variable]
  char ans[101];
       ^~~