#include <iostream>
#include <string>
#include <algorithm>
#include <cstdio>
#include <vector>
#include <cmath>
#include <stack>
#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
using namespace std;

int main(){
    int n;
    cin >> n;
    REP(i, n){
    	string s1, s2;
    	cin >> s1 >> s2;
    	int len1 = s1.length(), len2 = s2.length();
    	if (len1 > 80 || len2 > 80) {
    		cout << "overflow" << endl;
    	} else {
    		int num1[100] = {0}, num2[100] = {0}, ans[100] = {0};
    		REP(j, len1){
    			num1[j] = s1[len1-1-j] - '0';
    		}
    		REP(j, len2){
    			num2[j] = s2[len2-1-j] - '0';
    		}
    		int ll = len1 > len2 ? len1 : len2;
    		REP(j, ll){
    			ans[j] += num1[j] + num2[j];
    			if (ans[j]/10 > 0) {
    				ans[j+1]++;
    				ans[j] -= 10;
    			}
    		}
    		if (ans[80] > 0){
    			cout << "overflow" << endl;
    		} else {
    			if (ans[ll] > 0) cout << ans[ll];
    			REP(j, ll){
    				cout << ans[ll-1-j];
    			}
    			cout << endl;
    		}
    	}
    }
}
