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

using namespace std;

int main(int argc, char* argv[])
{
	int i;
	int num, pos;
	int len1, len2;
	char temp;
	char f1[101] = { 0 }, f2[101] = { 0 };
	int  up[100] = { 0 };
	int  sum[101] = { 0 };

	cin >> num;
	while (num--) {
		cin >> f1;
		cin >> f2;

		len1 = strlen(f1);
		len2 = strlen(f2);
		if (len1 > 80 || len2 > 80) {
			cout << "overflow" << endl;
			continue;
		}

		for (int i = 0; i < len1 / 2; i++) {
			temp = f1[i];
			f1[i] = f1[len1 - 1 - i];
			f1[len1 - 1 - i] = temp;
		}
		for (int i = 0; i < len2 / 2; i++) {
			temp = f2[i];
			f2[i] = f2[len2 - 1 - i];
			f2[len2 - 1 - i] = temp;
		}

		for (i = 0; i < len1; i++) f1[i] = f1[i] - 0x30;
		for (i = 0; i < len2; i++) f2[i] = f2[i] - 0x30;

		for (int i = 0; i < 100; i++) {
			sum[i] += (f1[i] + f2[i]);
			if (sum[i] >= 10) {
				sum[i] -= 10;
				sum[i + 1]++;
			}
		}

		for (pos = 100; sum[pos] == 0; pos--) {}
		if (pos >= 80) {
			cout << "overflow";
			break;
		}
		for (int i = pos; i >= 0; i--) {
			cout << sum[i];
		}
		cout << endl;
	}
return 0;
}