/in/foo.cc: In function 'int txz(std::__cxx11::string, int, int)':
/in/foo.cc:5:7: warning: statement has no effect [-Wunused-value]
  for(i;i<=y;i++) s+=a[i]-78;
       ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:15:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<s.length();i++){
                ^
/in/foo.cc:16:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int j=i;j<s.length();j++) {
                  ^