#include <iostream>
#include <sstream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <algorithm>
#include <functional>

using namespace std;

class LargeInteger
{
private:
	vector<int> places;
public:
	LargeInteger( string number )
	{
		reverse( number.begin(), number.end() );

		for ( unsigned int i = 0; i < number.length(); i++ )
		{
			this -> places.push_back( number[i] - '0' );
		}

		return;
	}

	LargeInteger& operator += ( string number )
	{
		reverse( number.begin(), number.end() );

		for ( unsigned int i = 0; i < number.length(); i++ )
		{
			if ( i < places.size() )
			{
				this -> places[i] += number[i] - '0';
			}
			else
			{
				this -> places.push_back( number[i] - '0' );
			}
		}

		return *this;
	}

	void printNumber()
	{
		adjust();

		if ( places.size() < 80 )
		{
			for ( vector<int>::reverse_iterator it = places.rbegin(); it != places.rend(); it++ )
			{
				cout << *it;
			}
		}
		else
		{
			cout << "overflow";
		}
		cout << endl;
		
		return;
	}
	
	void adjust()
	{
		for ( unsigned int i = 0; i < places.size(); i++ )
		{
			if ( 10 <= places[i] )
			{
				if ( i + 1 < places.size() )
				{
					places[i+1] += places[i] / 10;
				}
				else
				{
					places.push_back( places[i] / 10 );
				}
				places[i] %= 10;
			}
		}

		return;
	}
};


int main()
{
	int n;
	string buffer;

	cin >> n;

	for ( int i = 0; i < n; i++ )
	{
		cin >> buffer;
		LargeInteger li( buffer );

		cin >> buffer;
		li += ( buffer );

		li.printNumber();
	}

	return 0;
}