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

int main()
{
	string s1, s2, temp;
	int sum, flag;
	int a, b;
	vector<int> v;
	int T;
	cin >> T;
	while (T--)
	{
		cin >> s1 >> s2;
		v.clear();
		sum = 0;
		flag = 0;
		reverse(s1.begin(), s1.end());
		reverse(s2.begin(), s2.end());
		if (s1.size() < s2.size())
		{
			temp = s1;
			s1 = s2;
			s2 = temp;
		}
		for (int i = 0; i < s1.size(); ++i)
		{
			if (s1[i] == '0')a = 0;
			else if (s1[i] == '1')a = 1;
			else if (s1[i] == '2')a = 2;
			else if (s1[i] == '3')a = 3;
			else if (s1[i] == '4')a = 4;
			else if (s1[i] == '5')a = 5;
			else if (s1[i] == '6')a = 6;
			else if (s1[i] == '7')a = 7;
			else if (s1[i] == '8')a = 8;
			else if (s1[i] == '9')a = 9;
			if (i >= s2.size())b = 0;
			else
			{
				if (s2[i] == '0')b = 0;
				else if (s2[i] == '1')b = 1;
				else if (s2[i] == '2')b = 2;
				else if (s2[i] == '3')b = 3;
				else if (s2[i] == '4')b = 4;
				else if (s2[i] == '5')b = 5;
				else if (s2[i] == '6')b = 6;
				else if (s2[i] == '7')b = 7;
				else if (s2[i] == '8')b = 8;
				else if (s2[i] == '9')b = 9;
			}
			sum = a + b + flag;
			if (sum > 9)
			{
				sum = sum - 10;
				flag = 1;
			}
			else
			{
				flag = 0;
			}
			v.push_back(sum);
		}
		if (flag == 1)
			v.push_back(1);
		if (v.size() > 80)
			cout << "overflow" << endl;
		else
		{
			for (int i = v.size() - 1; i >= 0; --i)
			{
				cout << v[i];
			}
			cout << endl;
		}
	}
	return 0;
}