/in/foo.cc: In member function 'll node2::query()':
/in/foo.cc:41:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = 0; i < V.size(); i++)
                         ~~^~~~~~~~~~
/in/foo.cc: In function 'void gen()':
/in/foo.cc:61:15: warning: unused variable 'w' [-Wunused-variable]
     int i, j, w;
               ^
/in/foo.cc: In function 'node2 Merge(node2, node2, int*)':
/in/foo.cc:135:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < a.V.size(); i++)
                     ~~^~~~~~~~~~~~
/in/foo.cc:137:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < b.V.size(); i++)
                     ~~^~~~~~~~~~~~
/in/foo.cc: In function 'void solve(int, int)':
/in/foo.cc:193:31: warning: format '%d' expects argument of type 'int', but argument 2 has type 'll {aka long long int}' [-Wformat=]
     printf("%d\n",temp.query());
                               ^