/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:16:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(u == querys.size())
     ~~^~~~~~~~~~~~~~~~
/in/foo.cc:28:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<g[idx].size(); i++)
               ~^~~~~~~~~~~~~~
/in/foo.cc:35:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=1; j<cur.size(); j++)
                ~^~~~~~~~~~~
/in/foo.cc:41:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=1; j<cur.size(); j++)
                ~^~~~~~~~~~~
/in/foo.cc: In function 'void Solve()':
/in/foo.cc:62:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<str.size(); i++)
               ~^~~~~~~~~~~