11-(     )=2

17-(     )=11

14-(     )=6

19-(     )=7

17-(     )=7

15-(     )=3

13-(     )=6

20-(     )=13

15-(     )=15

12-(     )=10

12-(     )=10

11-(     )=4

12-(     )=0

15-(     )=7

20-(     )=14

13-(     )=4

15-(     )=15

12-(     )=2

13-(     )=3

13-(     )=8

15-(     )=13

12-(     )=8

19-(     )=13

20-(     )=11

20-(     )=4

15-(     )=15

18-(     )=0

13-(     )=8

17-(     )=12

14-(     )=10

20-(     )=10

19-(     )=0

18-(     )=11

20-(     )=4

20-(     )=16

13-(     )=3

12-(     )=1

15-(     )=12

19-(     )=3

16-(     )=6

15-(     )=14

14-(     )=11

14-(     )=12

18-(     )=8

15-(     )=7

16-(     )=4

18-(     )=17

20-(     )=6

20-(     )=8

12-(     )=1