1: 2, 3 2: 1, 2, 4 3: 2, 4 4: 2 5: 1, 2, 4 6: 2 7: 4, 1 8: 2 9: 3 10: 2 11: 1 12: 2, 4 13: 4 54: 1 15: 4 16: 2 17: 1 18: 3 19: 4 20: 3
