#include "stdio.h" int numReverse(int num){ int sum = 0; while (num!=0){ sum = sum*10 + num%10; num = num/10; } return sum; } int main(){ int num1,num2;int sum1,sum2; while (scanf("%d%d",&num1,&num2)!=EOF){ sum1 = num1 + num2; num1 = numReverse(num1); num2 = numReverse(num2); sum2 = num1 + num2; if(sum1 == numReverse(sum2)) printf("%d\n",sum1); else printf("NO\n"); } }