#include <iostream>
#include <string>
#include <algorithm>
using namespace std;

int n;

int main()
{
	cin >> n;

	for (int i = 0; i < n; i++) {
		string s, t;

		cin >> s >> t;

		int v = s.size(), w = t.size();

		if (v < w) {
			string y = s;
			s = t;
			t = y;

			swap(v, w);
		}

		int k = 0;
		string u;

		for (int i = 0; i < v; i++) {
			k += s[v - i - 1] - '0';

			if(i < w)
				k += t[w - i - 1] - '0';

			u = (char)('0' + (k % 10)) + u;
			k /= 10;
		}

		if (k > 0)
			u = '1' + u;

		if (u.size() <= 80)
			cout << u << endl;
		else
			cout << "overflow" << endl;
	}

	return 0;
}
