2 9 2 9 1 3 July 8, 2019 16 32 64 128 2 2 9 1 3 4 2 2 9 3 1 5 2 9 2 x 1 3 Y 3 2 9 x 1 2 9 1 2 3x 1 9 x 2 1 9 3 2 9 2 1 9 x 4 5 9