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