def append_and_compress(coin_pairs, coin):
    if not coin_pairs or coin_pairs[-1][0] != coin:
        return coin_pairs + ((coin, 1),)
    else:
        return coin_pairs[:-1] + ((coin_pairs[-1][0], coin_pairs[-1][1] + 1),)


def change(n, coins, choices):
    if n == 0:
        print(coins)
    elif n > 0 and choices:
        change(n - choices[0], append_and_compress(coins, choices[0]), choices)
        change(n, coins, choices[1:])


def main():
    change(7, (), (50, 20, 15, 10, 5, 3, 2, 1))


if __name__ == '__main__':
    main()