2 7 x 14 15 July 8, 2019 16 32 64 128 2 7 x 14 15 x (- 1 2 9 2 7 x 14 15 3 11 x 7 2 x 14 15 1 2 x 3 7 x 14 15 6 7 1 2 x 14 15 9 14 x 7 2 x 8 15 14 x 7 2 7 x 15 2 7x ≥-14 14 2 x 7
