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

int main(void)
{
	int n;
	cin >> n;
	for (int i = 0; i < n; i++)
	{
		int kuriage = 0;
		int sum[200] = {};
		string a, b;
		bool f = true;
		cin >> a >> b;
		int sizea = a.size(), sizeb = b.size();
		if (sizea > 80 || sizeb > 80) f = false;
		else
			for (int j = 0; j < max(sizea, sizeb); j++)
			{
				if (sizea > j && sizeb > j) sum[j] = (a[sizea - j - 1] - '0') + (b[sizeb - j - 1] - '0') + kuriage;
				else if (sizea > j) sum[j] = (a[sizea - j - 1] - '0') + kuriage;
				else if (sizeb > j) sum[j] = (b[sizeb - j - 1] - '0') + kuriage;
				kuriage = 0;
				if (sum[j] > 9)
				{
					kuriage++;
					sum[j] -= 10;
				}
			}
			sum[max(sizea, sizeb)] = kuriage;
			int count = max(sizea, sizeb);
			while (sum[count] == 0 && count > 0) count--;
			if (count >= 80 || f == false) cout << "overflow" << endl;
			else
			{
				for (int j = count; j >= 0; j--)
					cout << sum[j];
				cout << endl;
			}
	}
	return 0;
}
