// class point	の練習（クラスの高度な実装）
#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <string>
#include <cmath>
#include <queue>


typedef long long llong;
using namespace std;
#define MAX 100010

int main() {
	string number_A;
	string number_B;
	string sum;
	int N;
	int sum_size;

	cin >> N;

	for (int i = 0; i < N; i++) {
		cin >> number_A;
		cin >> number_B;
		if (number_A.size() > 80 || number_B.size() > 80)cout << "overflow\n";
		else {
			sum_size = max(number_A.size(), number_B.size());
			sum.resize(sum_size);
			while (number_A.size() != sum_size) {
				number_A.insert(0, "0");
			}
			while (number_B.size() != sum_size) {
				number_B.insert(0, "0");
			}
			for (int j = 0; j < min(number_A.size(), number_B.size()); j++) {
				sum[j] = number_A[j]-48 + number_B[j];
			}
			for (int j = sum_size-1; j >=0; j--) {
				if (sum[j]>57) {
					sum[j] -= 10;
					if(j!=0) sum[j - 1] += 1;
					else sum.insert(0, "1");
				}
			}
			if (sum.size() > 80) cout << "overflow\n";
			else cout << sum << endl;


		}
	}

	return 0;
}
 
