#include <iostream>
#include <string>

using namespace std;

int main() {
	int N; cin >> N;
	for (int i=0; i<N; i++) {
		string a, b;
		cin >> a >> b;
		int sum, ret=0;
		if (a.length() > b.length()) {
			int l = b.length()-1;
			for (int i=a.length()-1; i>=0; i--) {
				if (l >= 0) {
					sum = (a[i]-48)+(b[l]-48)+ret;
					l--;
				} else {
					sum = (a[i]-48)+ret;
				}
				if (sum>=10) {
					ret = sum/10;
					sum -= ret*10;
				} else {
					ret = 0;
				}
				a[i] = sum+48;
			}
			if (ret != 0) {
				a.insert(a.begin(), ret+48);
			}
			if (a.length() > 80) cout << "overflow" << endl;
			else cout << a << endl;
		} else {
			int l = a.length()-1;
			for (int i=b.length()-1; i>=0; i--) {
				if (l >= 0) {
					sum = (a[i]-48)+(b[i]-48)+ret;
					l--;
				} else {
					sum = (a[i]-48)+ret;
				}
				if (sum>=10) {
					ret = sum/10;
					sum -= ret*10;
				} else {
					ret = 0;
				}
				b[i] = sum+48;
			}
			if (ret != 0) {
				b.insert(b.begin(), ret+48);
			}
			if (b.length() > 80) cout << "overflow" << endl;
			else cout << b << endl;
		}
	}
	return 0;
}