#include <iostream>
#include <cstring>
#include <algorithm>
#include <sstream>
using namespace std;

string error = "overflow";

int main(){
	ios::sync_with_stdio(false);
	cout.sync_with_stdio(false);
	int n;
	cin >> n;
	bool over[n];
	int keta[n];
	string a[n], b[n];
	char c[n][81]; 
	for(int i = 0; i < n; i++){
		for(int j = 0; j < 81; j++){
			c[i][j] = '0';
		}
	}
	for(int i = 0; i < n; i++){
		over[i] = false;
		keta[i] = 0;
		int extra = 0;
		cin >> a[i] >> b[i];
		if(a[i].size() < b[i].size()){
			swap(a[i],b[i]);
		}
		
		for(int j = 0; j < a[i].size(); j++){
			int p, q, num;
			stringstream sa, sb, sc;
			sa << a[i][a[i].size()-j-1];
			sa >> p;
			if(j < b[i].size()){
				sb << b[i][b[i].size()-j-1];
				sb >> q;
			}
			else{
				q = 0;
			}
			if(p+q+extra < 10){
				sc << p+q+extra;
				sc >> c[i][j];
				extra = 0;
			}
			else{
				int kurai;
				kurai = (p+q+extra)%10;
				sc << kurai;
				sc >> c[i][j];
				extra = 1;
				if(j == a[i].size()-1){
					c[i][a[i].size()] = '1';
					keta[i] = 1;
				}
			}
		}
		if(c[i][80] != '0'){
			over[i] = true;
		}
	}
	for(int i = 0; i < n; i++){
		if(over[i] == true){
			cout << error;
		}
		else{
			for(int j = 0; j < a[i].size()+keta[i]; j++){
			cout << c[i][a[i].size()+keta[i]-j-1];
			}
		}
		cout << endl;
	}
}