def quickestWayUp(ladders, snakes):
    n_moves = [-1]*101
    n_moves[1] = 0
    todo = [1]
    ladders_dict = {min(i,j): max(i,j) for i, j in ladders}
    snakes_dict = {max(i,j): min(i,j) for i, j in snakes}
    while todo:
        start = todo.pop()
        for x in range(start + 1, start + 7):
            x = ladders_dict.get(x, snakes_dict.get(x, x))
            if x > 100:
                break
            if (n_moves[x] == -1) or (n_moves[x] > n_moves[start] + 1):
                n_moves[x] = n_moves[start] + 1
                todo.append(x)
    return n_moves[100]