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

int main(){
	string sx, sy, sans;
	int n;
	getline( cin, sx );
	sscanf( sx.c_str(), "%d", &n );
	for( int i=0; i<n; i++ ){
		getline( cin, sx );
		getline( cin, sy );
		if( sx.length()>80 || sy.length()>80 ){
			cout << "overflow" << endl;
		}else{
			string &s = (sx.length()>sy.length())?sx:sy;
			string &sa = (sx.length()>sy.length())?sy:sx;
			sans.resize( s.length()+1 );
			for( int j=0; j<sans.length(); j++ )
				sans[j] = 0;
			for( int j=0; j<sa.length(); j++ ){
				sans[j] += (sa[sa.length()-1-j]-'0') + (s[s.length()-1-j]-'0');
				if( sans[j] > 9 ){
					sans[j] -= 10;
					sans[j+1]++;
				}
			}
			for( int j=sa.length(); j<s.length(); j++ ){
				sans[j] += s[s.length()-1-j]-'0';
				if( sans[j] > 9 ){
					sans[j] -= 10;
					sans[j+1]++;
				}
			}
		}
		if( sans.length()>80 && sans[sans.length()-1]>0 ){
			cout << "overflow" << endl;
		}else{
			for( int j=(sans[sans.length()-1]==0?sans.length()-2:sans.length()-1); j>=0; j-- ){
				cout << (int)sans[j];
			}
			cout << endl;
		}
	}
	return 0;
}