/in/foo.cc: In function 'int main()':
/in/foo.cc:8:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
      for(int i=0;i<=strlen(b);i++){
                   ^
/in/foo.cc:11:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (sum>=strlen(b)/2)cout<<"Yes"<<endl;
          ^