#include <algorithm>
#include <sstream>
#include <iostream>
#include <list>
#include <map>
#include <math.h>
#include <stack>
#include <stdio.h>
#include <string>
#include <queue>
#include <vector>
using namespace std;


stack<int> A;
int y = 0;
int NIL = -1;
int MAX = 80;

vector<int> conv(string s) {
	vector<int> V(MAX, NIL);
	int i;
	for (i = 0; i < s.length(); i++) V[MAX - 1 - i] = s[s.length() - 1 - i] - '0';

	return V;
}

void push(int a, int b) {
	int x = a + b;
	if (y > 0) x += y; y = 0;
	if (x > 9) {
		A.push(x % 10);
		y = 1;
	}
	else {
		A.push(x);
	}
}

int main()
{
	int n;

	string a, b;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> a >> b;
		if (a.length() > 80 || b.length() > 80) {
			cout << "overflow" << endl;
			continue;
		}

		A = stack<int>();
		vector<int> V1 = conv(a);
		vector<int> V2 = conv(b);

		for (int i = MAX - 1; i >= 0; i--) {
			if (V1[i] != NIL && V2[i] != NIL) {
				push(V1[i], V2[i]);
			}
			else if (V1[i] == NIL && V2[i] != NIL) {
				push(V2[i], 0);
			}
			else if (V2[i] == NIL && V1[i] != NIL) {
				push(V1[i], 0);
			}
		}

		if (y == 1) {
			A.push(1);
			y = 0;
		}

		if (A.size() > 80) {
			cout << "overflow";
		}
		else {
			while (A.size() != 0) {
				cout << A.top(); A.pop();
			}
		}

		cout << endl;
	}
}
