时间限制：1 秒

内存限制：32 兆

特殊判题：否

提交：3452

解决：1892

//Asimple
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cctype>
#include <cstdlib>
#include <stack>
#include <cmath>
#include <set>
#include <map>
#include <string>
#include <queue>
#include <limits.h>
#define INF 0x7fffffff
#define mod 1000000000
using namespace std;
const int maxn = 10001;
typedef long long ll;
int n, x, y;

int reverse(int n){//获取反转 
    int sum = 0;
    while( n ){
        sum *= 10;
        sum += n%10;
        n /= 10;
    }
    return sum;
}
 
int main(){
    cin >> n;
    while( n -- ){
        cin >> x >> y;
        if( reverse(x)+reverse(y) == reverse(x+y)){
            cout << x+y << endl;
        } else {
            cout << "NO" << endl;
        }
    }
    return 0;
}