/in/foo.cc: In function 'int main()':
/in/foo.cc:28:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 for(int j=0;j<=flag[i].size()-1;j++)
             ~^~~~~~~~~~~~~~~~~~
/in/foo.cc:38:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 for(int j=0;j<=flag[i].size()-1;j++)
             ~^~~~~~~~~~~~~~~~~~