Question 103
Given a $2n \times 2n$ table all the cells being white. Per move it is allowed to change the color of any three consecutive cells in any row or in any column (white cell is replaced by black one and vice versa).
Find all possible values of $n \ge 2$ for which one can obtain the chess coloring of the given table.
(E. Barabanov)
Find all possible values of $n \ge 2$ for which one can obtain the chess coloring of the given table.
(E. Barabanov)