#include <iostream>
#include <string>
#include <utility>
#include <algorithm>
#include <queue>
#include <map>
#include <fstream>
#include <array>
#include <utility>
#include <functional>
#include <stack>

using namespace std;
typedef long long Int;
#define REP(i , x) for(Int i = 0 ; i < x ; ++i)

typedef pair<int, int> P;


int main()
{
	int n;
	cin >> n;
	REP(i, n){
		string a, b;
		int a_a[100] = { 0 };
		int b_a[100] = { 0 };
		int c_a[100] = { 0 };
			cin >> a >> b;
			if (a.length() > 80 || b.length() > 80){
				cout << "overflow" << endl;
				continue;
			}

			REP(i, a.length()){
				a_a[i] = a[a.length() - i -1] - '0';
			}
			
			REP(i, b.length()){
				b_a[i] = b[b.length() - i -1] - '0';
			}

			REP(i, 84){
				int temp = a_a[i] + b_a[i] + c_a[i];
				c_a[i + 1] += temp / 10;
				c_a[i] = temp % 10;
			}

			int i = 84;

			while (!c_a[i] && i){
				--i;
			}
			if (i > 80){
				cout << "overflow" << endl;
				continue;
			}

			while (i >= 0){
				cout << c_a[i];
				--i;
			}
			cout << endl;
		}

	return 0;
}