#include <iostream>
#include <string>
#include <stack>
#include <math.h>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <vector>

using namespace std;


bool f(long long x) {
	if (log10(x) >= 80) return false;
	else return true;
}



int main()
{
	int n;
	cin >> n;
	long long a;
	long long b;
	while(cin>>a){
		cin >> b;
		if (f(a) && f(b) && f(a + b)) cout << a + b << endl;
		else cout << "overflow" << endl;
	}
	

}