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=
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=