12-4=

4+14=

17-17=

12-0=

19-16=

14-9=

15-2=

11-8=

1+17=

15+4=

15-11=

17-0=

6+11=

18-6=

12-6=

0+16=

2+15=

6+11=

17-6=

16+2=

13-12=

13-9=

20-15=

12-0=

12-2=

2+11=

19+1=

17-5=

3+9=

6+12=

13-5=

13-9=

2+18=

3+16=

17-14=

20-14=

9+9=

16+0=

17-13=

10+2=

16-1=

6+10=

0+20=

16-8=

5+13=

19+0=

18+0=

13-9=

15+5=

14-9=