14 + 5 = 19
19 − 2 = 17
17 − 5 = 12
12 + 6 = 18
18 − 2 = 16
16 + 4 = 20
20 − 2 = 18
18 − 2 = 16
16 − 2 = 14
14 + 1 = 15