0 X X X X X X X X X X X X X X X X X X X X X 0 0 X X X X X X X X X X X X X X X X X X X X X 0 1 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 0 2 X X X X X X X X X X X X X X X X X X X X X 0 3 X X X X X X X X X X X X X X X X X X X X X 0 4