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