20-(30-37)+(18-25)-(-7)-(+20)
(-8)+(+3)+(+5)
(-6)-(-8)
(+15)+(+7)+(+8):
7-(32-45)-6+(12-45):
(+12)-(-35)
(-12)-(+35)
(-8)+(+3)
0
-5
7
-47
47
2
30
-19
