2+1= 4- 1= 6-3= 5+2= 6+1=
5-3= 3+0= 2+4= 4-0= 5-5=
6-2= 1+1= 7-3= 5-1= 3+3=
7-5= 5+1= 3+1= 4- 3= 7-6=
□○□=□ □○□=□
