/in/foo.cc: In function 'void dfs(long long int, long long int)':
/in/foo.cc:12:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(long long int i=0;i<g[root].size();i++)
                        ~^~~~~~~~~~~~~~~
/in/foo.cc:16:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(long long int i=0;i<g[root].size();i++)
                        ~^~~~~~~~~~~~~~~
/in/foo.cc:19:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(long long int i=0;i<g[root].size();i++)
                        ~^~~~~~~~~~~~~~~
/in/foo.cc:22:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(long long int i=0;i<g[last].size();i++)
                        ~^~~~~~~~~~~~~~~
/in/foo.cc:11:16: warning: unused variable 'Max' [-Wunused-variable]
  long long int Max=0;
                ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:32:25: warning: unused variable 'y' [-Wunused-variable]
  long long int n,root,x,y,w;
                         ^
/in/foo.cc:32:27: warning: unused variable 'w' [-Wunused-variable]
  long long int n,root,x,y,w;
                           ^