In Donguri Yama (どんぐりやま, which means "Acorn Mountain" in English), players attempt to build an eight-level pyramid of cards. Cards show numbers from 0 to 5, with the numbers showing in the upper left- and right-hand corners as well as in the middle of the bottom edge. The bottom row of the pyramid is eight cards wide, and players can place a card in the second row on top of two other cards as long as the sum or difference of the two supporting cards equals the card being placed. On top of an adjacent 1 and 3, for example, you can place either a 2 or a 4. Since the deck contains cards from 0-5, an adjacent 4 and 5 can have only a 1 placed on top of them. Players need to keep these restrictions in mind as they work their way to the top of the pyramid. Can you reach the summit?