#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
using namespace std;

int main(){

	int n;

	string a, b;
	char N1[80], N2[80];
	char sum[80], temp[82];
	string ans;

	cin >> n;

	for( int i=0;i<n;i++ ){

		cin >> a;
		
		cin >> b;

		if( a.length() > 80 ){
			cout << "overflow" << endl;
			continue;
		}

		if( b.length() > 80 ){
			cout << "overflow" << endl;
			continue;
		}

		for( int i=0;i<80;i++ ){
			N1[i] = -1; N2[i] = -1; sum[i] = 0;
		}

		for( int i=1;i<=a.length();i++ )
			N1[i] = a[a.length()-i] - '0';
		for( int i=1;i<=b.length();i++)
			N2[i] = b[b.length()-i] - '0';

		int over = 0;
		
		for( int i=0;i<80;i++ ){


			if( N1[i] == -1 && N2[i] == -1 ){
				if( over >= 10 ){
					sum[i] = over / 10;
					over = 0;
				}else
					sum[i] = -1;
				continue;
			}

			if( N1[i] != -1 )
				sum[i] += N1[i];
			if( N2[i] != -1 )
				sum[i] += N2[i];

			sum[i] += over / 10;

			over = floor((double)sum[i]/10)*10;

			sum[i] -= over;
			
		}

		if(over > 0)cout << "overflow" << endl;
		else{
			int j=0;
			for( int i=1;i<80;i++ ){
				if( sum[80-i] >= 0 ){
					temp[j] = sum[80-i] + '0';
					j++;
					continue;
				}
				
			}
			temp[j] = '\0';

			ans = temp;

			


			cout << ans << endl;
		}

	}
	return 0;
}