13+1= 10-3= 3-1= 2-1= 14-10= 17-8= 6+1= 17-6= 5+1= 2-2= 1+3= 6-0= 4-2= 6+2= 4+16= 20-13= 14-2= 9-1= 3+4= 3+2= 17-10= 17-0= 5+1= 5+2= 13+2= 8-8= 17-12= 18-8= 10-0= 0+2= 20-5= 16-5= 20-17= 7+4= 7+8= 13-4= 13-7= 8-0= 9+1= 19-7= 9-9= 0+14= 18-3= 12-0= 17-7= 2+3= 16-16= 2+12= 3+14= 5+6=