#include<iostream>
#include<string>
#include<vector>
using namespace std;

int main(){
	string a,b;
	vector<int> sum;
	int al, bl, sl;
	int n, up, num;
	cin >> n;
	for(int i=0;i<n;++i){
		cin >> a >> b;
		al = a.size()-1;
		bl = b.size()-1;
		up = 0;
		while(al >= 0 || bl >= 0){
			num = up;
			if(al>=0) num += a[al] - 48;
			if(bl>=0) num += b[bl] - 48;
			if(num > 9){
				sum.push_back(num - 10);
				up = 1;
			}else{
				sum.push_back(num);
				up = 0;
			}
			al -= 1;
			bl -= 1;
		}
		if(up == 1){
			sum.push_back(1);
		}
		sl = sum.size();
		if(sl > 80){
			cout << "overflow" << endl;
		}else{
			for(int j=sl-1;j>=0;--j){
				cout << sum[j];
			}
			cout << endl;
			sum.clear();
		}
	}
	return 0;
}