11-3=
15+2=
5+13=
9+6=
2+1=
16-14=
1+8=
4+12=
3+13=
14-3=
18-5=
7+6=
12+1=
12-1=
19-15=
18-1=
13-11=
16+1=
9-2=
16-7=
16-15=
18-14=
18-5=
16+4=
20-16=
17-5=
20-19=
10-5=
11-4=
1+8=
16-11=
17-5=
6+2=
6+10=
14-9=
18-11=
2+13=
6+8=
13-12=
13-3=
8+5=
19-4=