#include <iostream>
#include <algorithm>
#include <string>

using namespace std;

int main ( void )
{
	int n;

	while ( cin >> n )
	{
		for (int i = 0; i < n; ++i)
		{
			string s1, s2, out = "";
			cin >> s1 >> s2;

			reverse(s1.begin(), s1.end());
			reverse(s2.begin(), s2.end());

			int a, b, c, len = min(s1.size(), s2.size());

			for (int j = c = 0; j < len; ++j)
			{
				int x = (s1[j] - '0') + (s2[j] - '0') + c;
				c = x / 10;
				out += (x % 10 + '0');
			}

			string s;

			if (len == s1.size())
				s = s2;
			else
				s = s1;
			
			for (int j = len; j < s.size(); ++j)
			{
				int x = (s[j] - '0') + c;
				c = x / 10;
				out += (x % 10 + '0');
			}

			if ( c )
			{
				out += '1';
			}

			reverse(out.begin(), out.end());
	
			if ( out.size() > 80 )
				cout << "overflow" << endl;
			else
				cout << out << endl;
		}
	}

	return 0;
}