11-2=9 12-3=9 13-4=9 16-7=9
11-3=8 12-4=8 13-5=8 16-8=8
11-4=7 12-5=7 13-6=7 16-9=7
11-5=6 12-6=6 13-7=6 18-9=9
11-6=5 12-7=5 13-8=5 17-8=9
11-7=4 12-8=4 13-9=4 17-9=8
11-8=3 12-9=3 14-5=9 14-8=6
11-9=2 15-6=9 14-6=8 14-9=5
15-7=8 14-7=7
15-8=7
15-9=6