foo.cc: In function ‘void dfs(int)’:
foo.cc:9:22: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
    9 |         for(int i=0;i<g[u].size();i++)
      |                     ~^~~~~~~~~~~~
foo.cc: In function ‘int main()’:
foo.cc:28:71: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
   28 |                 if(g[x].size()>g[xt].size()||g[x].size()==g[xt].size()&&x>xt)xt=x;
      |                                              ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
foo.cc:32:22: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   32 |         for(int i=1;i<g[xt].size();i++)
      |                     ~^~~~~~~~~~~~~