Problem
COM-B1-M08-P013 Piles \(12\) and \(17\)
#13
★★★☆☆ Level 3 of 5
There are two piles of \(12\) and \(17\) stones. In one move, a player may take any positive number of stones from one pile. The last move wins. Find a winning first move.
Make the piles equal.
Positions with equal piles are losing: the opponent can copy the move in the other pile. Therefore the first player should reduce the pile \(17\) to \(12\), taking \(5\) stones. After that, every second-player move is copied in the other pile, and the first player wins.
Move to a losing position in one move.