#include<iostream>
#include<stdio.h>
#include<string.h>

int n;
char a[256], b[256];
int temp[100], temp2[100];

int main()
{
        std::cin >> n;
	
	while( n-- ){
		memset( temp, 0, sizeof( temp ) );
		memset( temp2, 0, sizeof( temp2 ) );
		
		std::cin >> a >> b;
		
		int maxlen = std::max( strlen( a ), strlen( b ) );
		
		if( maxlen > 79 ){
			std::cout << "overflow" << std::endl;
		 	continue;
		}
		
		for( int i = 0; i < strlen( a ); i++ ){
			temp[strlen( a ) - i - 1] = a[i] - '0';
		}
		
		for( int i = 0; i < strlen( b ); i++ ){
			temp2[strlen( b ) - i - 1] = b[i] - '0';
		}
		
		for( int i = 0; i < maxlen; i++ ){
			temp[i+1] += ( temp[i] + temp2[i] ) / 10;
			temp[i] = ( temp[i] + temp2[i] ) % 10;
		}
		
		if( temp[maxlen] ){
		 	if( maxlen + 1 > 79 ){
				std::cout << "overflow" << std::endl;
				continue;
			}
			
			std::cout << temp[maxlen];
		}
		
		for( int i = maxlen - 1; i >= 0; i-- ){
		 	std::cout << temp[i];
		}
		std::cout << std::endl;
	}

 	return 0;
}