#include <stdio.h>
#include <iostream>
#include <string>

using namespace std;

int main() {

	string a;
	string b;
	int kari;

	cin >> kari;

	for (int o = 0; o < kari; o++) {
		int c[80] = {0};
		int d[80] = {0};
		int e[81] = {0};
		int counter = 0;

		cin >> a;
		cin >> b;
	
		if (a.size() > 80 || b.size() > 80) {
			cout << "overflow" << endl;
			continue;
		} else {
			for (int i = a.size() - 1; i >= 0; i--) {
				c[a.size() - 1 - i] = a[i] - '0';
			}

			for (int i = b.size() - 1; i >= 0; i--) {
				d[b.size() - 1 - i] = b[i] - '0';
			}

			for (int j = 0; j < 80; j++) {
				e[j] += c[j] + d[j];
				if (e[j] >= 10) {
					e[j+1] = e[j] / 10;
					e[j] = e[j] % 10;
				} 
			}
		}

		if (e[80] > 0) {
			cout << "overflow" << endl;
		} else {
			for (int k = 79; k >= 0; k--) {
				if (e[k] != 0) {
					counter = k;
					break;
				}
			}
			for (int k = counter; k >= 0; k--) {
				cout << e[k];
			}
			cout << endl;
		}
	}
	return 0;
}