F x x 2

F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2
F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2
F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2F x x 2