8
(-1, 1)
(0.1, 1.2)
(0.2, 2.3)
(0.3, 3.4)
(0.4, 4.5)
(0.5, 5.6)
(0.6, 6.7)
(0.7, 7.8)
(0.8, 8.9)
-1
1
9