def solution(src, dest):
    unvisited = [i for i in range(64)]
    curr_stage = set([src])
    moves = 0
    while dest not in curr_stage:
        next_stage = set()
        for curr in curr_stage:
            next_stage.update(possible_next_position(curr))
        moves += 1
        curr_stage = next_stage
    return moves

def possible_next_position(curr):
    result = []
    if curr % 8 >= 1:
        if curr / 8 >= 2:
            result += [curr-17]
        if curr / 8 <= 5:
            result += [curr+15]
    if curr % 8 >= 2:
        if curr / 8 >= 1:
            result += [curr-10]
        if curr / 8 <= 6:
            result += [curr+6]
    if curr % 8 <= 5:
        if curr / 8 >= 1:
            result += [curr-6]
        if curr / 8 <= 6:
            result += [curr+10]
    if curr % 8 <= 6:
        if curr / 8 >= 2:
            result += [curr-15]
        if curr / 8 <= 5:
            result += [curr+17]
    return set(result)


tests = [
        ([0, 1], 3),
        ([19, 36], 1),
        ([0, 0], 0),
        ]

for i, o in tests:
    result = solution(*i)
    print(i, result == o, result, o)