MathDB

Bethan is playing a game on an

n\times n

grid consisting of

n^2

cells. A move consists of placing a counter in an unoccupied cell

C

where the

2n-2

other cells in the same row or column as

C

contain an even number of counters. After making

M

moves Bethan realises she cannot make any more moves. Determine the minimum value of

M

.
United Kingdom, Sam Bealing

C1