Driver Code
int main ( ) { g [ 0 ] . push_back ( make_pair ( 1 , 0 ) ) ; g [ 0 ] . push_back ( make_pair ( 2 , 1 ) ) ; g [ 1 ] . push_back ( make_pair ( 2 , 2 ) ) ; g [ 1 ] . push_back ( make_pair ( 3 , 3 ) ) ; g [ 2 ] . push_back ( make_pair ( 3 , 4 ) ) ; g [ 3 ] . push_back ( make_pair ( 4 , 5 ) ) ; g [ 4 ] . push_back ( make_pair ( 2 , 6 ) ) ;