#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <complex>
#include <string>
#include <sstream>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <functional>
#include <iostream>
#include <map>
#include <set>
using namespace std;
typedef pair<int,int> P;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;
#define pu push
#define pb push_back
#define mp make_pair
#define eps 1e-9
#define INF 2000000000
#define sz(x) ((int)(x).size())
#define fi first
#define sec second
#define SORT(x) sort((x).begin(),(x).end())
#define all(x) (x).begin(),(x).end()
#define EQ(a,b) (abs((a)-(b))<EPS)
int main()
{
	int n;
	cin >> n;
	for(int i=0;i<n;i++)
	{
		string s1,s2;
		cin >> s1 >> s2;
		vector<int> ans;
		int k=0;
		for(int j=0;j<1000;j++)
		{
			int num=0;
			int a=s1.size()-1-j,b=s2.size()-1-j;
			if(a<0&&b<0&&k==0)break;
			if(a>=0)num+=s1[a]-'0';
			if(b>=0)num+=s2[b]-'0';
			ans.pb((num+k)%10);
			if(num+k>=10)k=1;
			else k=0;
		}
		if(ans.size()>80)
		{
			printf("overflow\n");
			continue;
		}
		for(int j=ans.size()-1;j>=0;j--)
		{
			cout << ans[j];
		}
		cout << endl;
	}
	return 0;
}