#include <iostream>
#include <sstream>
#include <cstring>

using namespace std;

int main()
{
	stringstream ss;
	string str;
	int n;
	long long num;
	
	cin >> n;
	while (n != 0){
		int sum = 0;
		for (int i = 0; i < 2; i++){
			cin >> str;
			ss.clear();
			ss.str("");
			ss << str;
			ss >> num;
			sum += num;
		}
		ss.clear();
		ss.str("");
		ss << sum;
		ss >> str;
		
		if (str.size() > 80){
				cout << "overflow" << endl;
				break;
		}
		else{
			cout << str << endl;
		}
		n--;
	}
	return (0);
}