примеры: 1+8= 3+44= 6+81= 71+11= 100-77= 1000+1+5+1=

1 + 8 = 9 3 + 44 = 47 6 + 81 = 87 71 + 11 = 82 100 - 77 = 23 1000 + 1 + 5 + 1 = 1007