#include <iostream>
#include <string>
#include <typeinfo>
#include <cmath>
#include <sstream>

using namespace std;

int main() {
	int n;
	cin >> n;

	string a, b, res;
	int temp, size, hoge, as, bs;
	for (int i = 0; i < n; i++) {
		cin >> a >> b;
		hoge = 0;
		res = "";

		as = a.size();
		bs = b.size();
		size = as > bs ? as : bs;
		while (a.size() < size) { a = "0" + a; }
		while (b.size() < size) { b = "0" + b; }

		for (int i = 0; i < size; i++) {
			temp = a[size-i-1]+b[size-i-1]-'0'-'0'+hoge;

			stringstream ss;
			ss << temp % 10;
			if (temp > 9) {
				res = ss.str() + res;
				hoge = temp / 10;
			}
			else {
				res = ss.str() + res;
				hoge = 0;
			}
		}

		stringstream ss;
		ss << hoge;
		if (hoge > 0) {
			res = ss.str() + res;
		}
		
		if (res.size() > 80) {
			cout << "overflow";
		}
		else {
			cout << res;
		}
		cout << endl;
	}
	return 0;
}