#include <iostream>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <algorithm>
#include <stdlib.h>

using namespace std;


int main(){

	int n;
	cin >> n;
	for(int i=0 ; i<n ; i++){
		string a, b;
		cin >> a;
		cin >> b;

		if(b.size() > a.size()){
			string temp;
			temp = a;
			a = b;
			b = temp;
		}

		if(a.size() > 80){
			cout << "overflow" << endl;
		}else{
			for(int j=0 ; j<b.size() ; j++){
				a[a.size()-1-j] = a[a.size()-1-j] + b[b.size()-1-j] -'0';
				if(a[a.size()-1-j] > '9'){
					a[a.size()-1-j] -= 10;
					for(int l=j ; l<a.size() ; l++){
						a[a.size()-2-l] ++;
						if(a[a.size()-2-l] > '9'){
							if(a.size()-2-l == 0){
								a = "0" + a;
							}
							a[a.size()-2-l] -= 10;
						}else break;
					}
				}
			}
			if(a.size() > 80){
				cout << "overflow" << endl;
			}else{
				cout << a << endl;
			}
		}

		}

	return 0;
}