The first question of 1 is too weak. Consider 2x2 first, and then one side will exceed 2 no matter which direction it changes.

This is a difficult problem in the world, and the existing achievements are as follows:

/c？ m = 9d 78d 5 13d 9 c 20 bb 8599d 837 e 7d 0 1d 6 1a 40 c 72362d 88 a 5339968449 e 07946040223 f 4 bb 507 f 574492942700 1 8 14 1465438p = 8057 c 9 16d 9c 7 1 1a 059 ebcc 2 f 545 f & amp； User = Baidu