No. Let the number of stones
in the three piles be \(a, b\) and \(c\),
respectively. Consider (mod \(3\)) of these
numbers. In the beginning, they are \(1, 2,
0\). After one operation, they become \(0, 1,
2\) no matter which two piles have stones
transfer to the third pile. So the
remainders are always \(0, 1, 2\) in some
order. Therefore, all piles having \(12 \) stones are impossible.