5+7
12
6+6
8+8
16
9+11
20
9+9
18
13+13
26
15+15
30
20+11
31
14+14
28
15+10
25
15-7
8
13-8
5
20-12
30-15
15
40+40
80
20+20
40
30+30
60
25+25
50
16-15
1