10 dollar = 5 beers;
5 beers = 5 bottles and 5 covers,
then recycle 4 bottles
2 more beers, which means 2 more bottles and 2 more covers,
we now have 7 covers ,can recycle again, get 1 beers, at hand, having
3 + 1 covers, 1 + 2 bottles .
haha, recycle 4 covers, get a free beer first, then have 4 bottles, then can
change to 2 beers.
again, we can one more beer. But finanlly 3 covers left and one bottle left,
it 's time to go home.
5 +2 +1 +2 +1 = 11 ?
The trick is to recycle cover or bottle first ?
