Wrong Answer
/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:13:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=0;j<v[i].size();j++){
~^~~~~~~~~~~~
/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:13:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=0;j<v[i].size();j++){
~^~~~~~~~~~~~
