/in/foo.cc: In function 'long long int test(long long int)':
/in/foo.cc:40:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0 ; i < r.length() ; i++)
                     ~~^~~~~~~~~~~~
/in/foo.cc: In function 'void derive(int)':
/in/foo.cc:53:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(ii = 0 ; ii < isf.size() ; ii++)
                      ~~~^~~~~~~~~~~~
/in/foo.cc:58:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(ii==isf.size())
            ~~^~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:70:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if(p == isf.size())
        ~~^~~~~~~~~~~~~