/in/foo.cc: In function 'int work(int, int)':
/in/foo.cc:32:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(j=1;j<s.length();j++)
           ~^~~~~~~~~~~
/in/foo.cc:39:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(j==s.length())
      ~^~~~~~~~~~~~
/in/foo.cc: At global scope:
/in/foo.cc:44:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main()
      ^