/in/foo.cc: In function 'void poto()':
/in/foo.cc:18:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int j=0;j<ve[i].size();j++){
                 ~^~~~~~~~~~~~~
/in/foo.cc:6:6: warning: unused variable 'ans' [-Wunused-variable]
  int ans=0,k=0;
      ^~~