{8: 1, 18: 1}
11 18
{8: 2, 18: 1, 1: 2, 11: 2}
{8: 2, 18: 2, 1: 2, 11: 2, 17: 3, 20: 1}
{8: 2, 18: 2, 1: 2, 11: 2, 17: 3, 20: 1, 5: 3}
{8: 2, 18: 3, 1: 2, 11: 3, 17: 4, 20: 1, 5: 3, 9: 3}
4