foo.cc: In function ‘int main()’:
foo.cc:19:31: warning: comparison of integer expressions of different signedness: ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} and ‘int’ [-Wsign-compare]
   19 |                 if(c[i].size()>=maxn)
      |                    ~~~~~~~~~~~^~~~~~
foo.cc:27:18: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   27 |         for(i=0;i<c[ans2].size();i++)
      |                 ~^~~~~~~~~~~~~~~
foo.cc:25:15: warning: ‘ans1’ may be used uninitialized [-Wmaybe-uninitialized]
   25 |         cout<<ans1<<endl<<ans2<<endl;
      |               ^~~~
foo.cc:7:23: note: ‘ans1’ was declared here
    7 |         int i,n,m,x,y,ans1,ans2,maxn=0;
      |                       ^~~~
foo.cc:7:28: warning: ‘ans2’ may be used uninitialized [-Wmaybe-uninitialized]
    7 |         int i,n,m,x,y,ans1,ans2,maxn=0;
      |                            ^~~~