There are 6 piles of peaches on the ground, with 12, 19, 20, 21, 22, and 25 peaches respectively. Two little monkeys took 5 piles of peaches from 6 piles. It is known that each little monkey takes an integer pile of peaches, and one little monkey takes four times as many peaches as the other little monkey. Ask how many peaches are in the last pile.
地上一共有6堆桃子，分别有12、19、20、21、22、25个桃子．两只小猴从6堆中拿走5堆桃子．已知每只小猴拿的都是整数堆的桃子，并且一只小猴拿的桃子数量是另一只小猴的4倍．问最后留下的一堆有多少只桃子．
<result>19</result>