/in/foo.cc: In function 'int main()':
/in/foo.cc:20:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(s.find(',')==-1&&s.find('.')==-1) {
      ~~~~~~~~~~~^~~~
/in/foo.cc:20:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(s.find(',')==-1&&s.find('.')==-1) {
                       ~~~~~~~~~~~^~~~
/in/foo.cc:31:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i=0; i<s.length(); i++) {
                 ~^~~~~~~~~~~