2-11= 3+2= 16-18= 7+18=
8-13= 2+2= 10+14= 8+14=
11+3= 17+10= 2+18= 12+18=
3-12= 9-7= 0+12= 13-12=
5+15= 14-15= 14+14= 9-19=
14+6= 14-19= 10-13= 0-9=
10-3= 18-17= 16-9= 13+8=
2-15= 13+14= 16-17= 19-13=
3+19= 17+13= 19+17= 19+14=
17+6= 12+9= 12-14= 12-16=