16 2 7 3 x1 1 July 8, 2019 16 32 64 128 7 16 14 x 3 1 2 1 2 x 1 3 8 x 7 16 bearing 1 5 16 x 2 2 3 x 3 1 7 16 ×2=8 16 7+16 7