Question 104
On infinite squared (grid) paper, $2006$ sides of $1 \times 1$ squares are painted black, all others are painted white. It is allowed to choose a square and to paint all its sides into opposite color. It is known that it is possible to make all square sides white in such manner. Whether is it enough
a) $260000$ repainting of square sides;
b) $250000$ repainting of square sides
for such repainting?
a) $260000$ repainting of square sides;
b) $250000$ repainting of square sides
for such repainting?