1в.
12+1= 17-1=
15+1= 13+1=
19+1= 1+16=
16-1= 10-1=
12-1= 18-1=
11+1= 10-1=
11-1= 13-1=
2в.
14+1= 15-1=
1+17= 18+1=
19-1= 20-1=
