也出一個game

An array of stones (N x M), two players taking turns removing stones.

When a stone is selected, the stones lie above and right are also removed.

The loser is the one ends up removing the last stone.

For instance, for 3x5 number of stones:

a b c d e

f g h i j

k l m n o

 

If a player selects the i stone,  d, e, i, j are all removed.

Does this game have a first mover advantage? What's your strategy?