8.164 Suppose there are 3 piles of stones, and A moves 1 stone from one pile to another each time. A can receive payment from B for each move, the amount of which is equal to the difference between the number of stones in the pile where the stone is placed and the number of stones left in the pile where the stone is taken from. If this difference is negative, A must return this amount of money to B (if A has no money to return, it can be temporarily owed). After several moves, all the stones are back in their original piles. Find the maximum amount of money A can earn at this point.
[Solution] The only value of the money that A can earn is 0, and of course, the maximum value is also 0. Suppose in each pile of stones, we use line segments to connect the stones in pairs. When A moves a stone, they first have to untie the line segments connecting the stone to all other stones in the pile (one end of these line segments still remains tied to the stone, only the end tied to other stones is untied), then move the stone along with these line segments to another pile, and connect the stone to all the stones in the new pile using the brought line segments. At this point, if there are line segments left without stones to connect, it indicates that the number of stones in the original pile is greater than the number of stones in the new pile. Thus, A can take off the excess line segments from this stone and claim money from B according to the number of line segments taken off. If the number of line segments brought by the stone is insufficient, it indicates that the number of stones in the original pile is less than the number of stones in the new pile. Thus, A will ask B for the remaining line segments to connect the stone to every stone in the new pile, and pay money (or owe) to B according to the number of line segments requested. Clearly, the rules described are consistent with the original problem.

In this way, it is easy to see that the total number of line segments connected in each pile and the total amount of money A gets from B remain unchanged during the process of moving stones. Since after moving several times, the distribution of all stones is the same as at the beginning, the amount of money A gets is also the same as before moving, which is of course 0.