{
    'A': {(0, 7), (1, 14), (15, 8), (9, 10), (11, 12), (13, 2), (3, 4), (5, 6)},
    'B': {(0, 1), (14, 15), (8, 9), (10, 11), (12, 13), (2, 3), (4, 5), (6, 7)},
    'C': {(0, 7), (1, 2), (14, 13), (15, 8), (9, 10), (11, 12), (3, 4), (5, 6)},
}
