Wrong Answer
/in/foo.cc: In function 'void dfs(int, int)':
/in/foo.cc:10:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<G[x].size();i++){
~^~~~~~~~~~~~
/in/foo.cc: In function 'void dfs(int, int)':
/in/foo.cc:10:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<G[x].size();i++){
~^~~~~~~~~~~~
