
#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <stack>
#include <cctype>
#include <complex>
#include <vector>
#include <algorithm>
#include <cstring>		//strlen

using namespace std;



bool solve(){
	char str1[10000],str2[10000];
	scanf("%s %s",str1,str2);
	int n1 = strlen(str1);
	int n2 = strlen(str2);	
	int n  = max(n1,n2);
	char str[10000];

	int c = 0;
	int i=0;
	while(i<n){
		int a = c;
		if(i<n1){
			a += (str1[n1-i-1]-'0');
		}
		if(i<n2){
			a += (str2[n2-i-1]-'0');
		}
		c = a/10; 
		a = a%10;
		
		str[i] = a + '0';
		i++;
	}
	if(c){
		str[i] = c + '0';
		i++;
	}
	
	if(i>81){
		cout<< "overflow"<<endl;
		return true;
	}
	
	for(int j=i-1;j>=0;j--){
		cout<< str[j];
	}
	cout<<endl;
	
	return true;
}

int main(){
	cout.setf(ios::fixed);
	cout.precision(5);
	int n;
	cin>> n;
	for(int i=0;i<n;i++){
		solve();
	}
	return 0;
}

 