Two people A and B play a game in the m×n grid (m,n∈N∗). Each person respectively (A plays first) draw a segment between two point of the grid such that this segment doesn't contain any point (except the 2 ends) and also the segment (except the 2 ends) doesn't intersect with any other segments. The last person who can't draw is the loser. Which one (of A and B) have the winning tactics? symmetryinductioncombinatorics proposedcombinatorics