#include <bits/stdc++.h>
using namespace std;

int main(void) {
	string str1, str2;
	int i1, i2;	
	vector<char> v;
	vector<char>::iterator it;
	int n; 
	cin >> n;
	while (n--) {
		cin >> str1 >> str2;
		if (str1.length() > 80 || str2.length() > 80) {
			cout << "overflow\n"; 
			continue;
		}
		int up = 0, n1, n2;
		char c;
		v.clear();
		if (str1.length() < str2.length())
			swap(str1, str2);
		for (i1 = str1.length() - 1, i2 = str2.length() - 1;
				i2 >= 0; i1--, i2--) {
			n1 = str1[i1] - '0';
			n2 = str2[i2] - '0';
			n1 = n1 + n2 + up;
			up = n1 / 10;
			n1 = n1 % 10;
			c = (char)(n1 + '0');
			v.push_back(c);
		}
		while (i1 >= 0) {
			n1 = str1[i1] - '0';
			n1 = n1 + up;
			up = n1 / 10;
			n1 = n1 % 10;
			c = (char)(n1 + '0');
			v.push_back(c);
			i1--;
		}
		if (up == 1) {
			v.push_back('1');
		}
		if (v.size() > 80) {
			cout << "overflow" << endl;
			continue;
		}
		reverse(v.begin(), v.end());
		for (it = v.begin(); it != v.end(); it++) {
			cout << *it;
		}
		cout << endl;
	}
}
