usage: nim n1 [n2 ...]
This program solves games of Nim. Nim is a two player game played with
an arbitrary number of heaps, each containing an arbitrary number of
stones. The two players take turns removing any number of stones from
any one pile. The player who removes the last stone wins.
Input is taken from the command line in the form of a list of numbers,
each representing a heap of stones.
For example, to solve a game of Nim with three heaps containing one,
two, and three stones, respectively, the following command line should
be used:
nim 1 2 3
If the game is a loss for the first player, "loss!" is printed. For a
win, "win!" is printed, followed by a list of available winning moves.