In the classic Towers of Hanoi problem, there are three pegs, labeled A, B and C, and n discs, of sizes 1 to n. Each disc has a hole in the center, so that it can be placed on a peg. Initially, all the discs are stacked on peg A in order of size, with the smallest disc on top. Only one disc may be moved at a time. In each move, you remove the top disc from one of the pegs, and place it on another peg. A disc may be placed on an empty peg or stacked on top of a larger disc, but it may not be placed on top of a smaller disc.
target is a string consisting of n characters, each of which is either A, B or C. The goal of the game is to make the minimum number of moves so that character i of target is the peg containing the disc of size i + 1. There is only one shortest sequence of moves. Return the state of the game after making moves of these moves, in the same format as target.
