#include <iostream>
#include <iomanip>
#include <algorithm>
#include <string>
#include <vector>
#include <set>
#include <map>
using namespace std;

int main() {
	string a;
	string b;
	int n;
	cin >> n;
	for (int i = 0; i < n;i++) {
		cin >> a >> b;
		string ans;
		if (a.size() < b.size()) {
			swap(a, b);
		}
		int back = 0;
		for (int j = 1; j <=a.size(); j++) {
			int d = a[a.size() - j] - '0' + b[b.size() - j] - '0' + back;
			ans = (char)(d % 10 + '0') + ans;
			back = d / 10;
		}
		if (back == 1) {
			ans = "1" + ans;
		}
		if (ans.size() > 80) {
			cout << "overflow" << endl;
		}
		else {
			cout << ans << endl;
		}
	}
	return 0;
}