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