4 6 1 4 3 9 July 8, 2019 16 32 64 128 6 1 4 9 3 8 1 6 4 3 9 2 4 7 x 6 1 4 7 x 3 9 4 1 6 х 9 3 4 4 1 6 x 9 3 4