#include <iostream>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>	// require sort next_permutation count __gcd reverse etc.
#include <cstdlib>	// require abs exit atof atoi 
#include <cstdio>		// require scanf printf
#include <functional>
#include <numeric>	// require accumulate
#include <cmath>		// require fabs
#include <climits>
#include <limits>
#include <cfloat>
#include <iomanip>	// require setw
#include <sstream>	// require stringstream 
#include <cstring>	// require memset
#include <cctype>		// require tolower, toupper
#include <fstream>	// require freopen
#include <ctime>		// require srand
#define rep(i,n) for(int i=0;i<(n);i++)
#define ALL(A) A.begin(), A.end()

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

string longlong_add (string str1, string str2 )
{
	string res = "";
	
	reverse (str1.begin(), str1.end() );
	reverse (str2.begin(), str2.end() );
	int len1 = str1.length();
	int len2 = str2.length();

	while (len1 != len2 ){
		if (len1 < len2 ){
			str1 += '0';
			len1 = str1.length();
		}else if (len1 > len2 ){
			str2 += '0';
			len2 = str2.length();
		} // end if
	} // end while

	bool carry = false;
	for (int i = 0; i < len1; i++ ){
		int num1 = str1[i] - '0';
		int num2 = str2[i] - '0';
		int sum = num1 + num2;

		sum += (carry ? 1 : 0 );

		if (sum < 10 ){
			res += sum + '0';
			if (carry){
				carry = false;
			} // end if
		}else{
			sum %= 10;
			res += sum + '0';
			carry = true;
		} // end if
	} // end for

	if (carry ){
		res += '1';
	} // end if

	reverse (res.begin(), res.end());

	return res;
}

int main()
{
//	cut here before submit 
//	freopen ("testcase.NB", "r", stdin );
	int n;
	scanf ("%d", &n );
	rep (i, n ){
		string a1, a2;
		cin >> a1 >> a2;
		bool ok = true;
		if (a1.length() > 80 && a2.length() > 80 ){
			ok = false;
		} // end if
		string add = longlong_add (a1, a2 );
		if (add.length() > 80 ){
			ok = false;
		} // end if
		if (ok ){
			cout << add << endl;		
		}else{
			printf ("overflow\n" );
		} // end if
	} // end rep

	return 0;
}