/in/foo.cc: In function 'void dfs1(int)':
/in/foo.cc:16:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < G[x].size(); i++)
                    ~~^~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:41:33: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'LL* {aka long long int*}' [-Wformat=]
         scanf("%d %d", &f, c + i);
                                 ^