#include <iostream>
#include <iomanip>
#include <sstream>
#include <stdio.h>
#include <vector>
#include <stack>
#include <queue>
#include <algorithm>
#include <math.h>
#include <utility>
#include <string>
#include <ctype.h>
#include <cstring>
#include <cstdio>
#include <sstream>
using namespace std;

#define FOR(i,k,n) for(int i = (k); i < (n); i++)
#define REP(i,n) FOR(i,0,n)
#define INF 114514810
#define ll long long
//#define scanf scanf_s

int main()
{
	int n;
	cin >> n;
	REP(i, n)
	{
		string a, b;
		vector<int> ans;
		cin >> a >> b;
		if (a.size() < b.size()) swap(a, b);
		bool kuri = 0;
		REP(i, b.size())
		{
			if (a[a.size()-i-1]-'0' + b[b.size()-1-i]-'0'+kuri < 10)
			{
				
				ans.push_back(a[a.size() - i - 1] - '0' + b[b.size() - 1 - i] - '0' + kuri);
				kuri = 0;
			}
			else
			{
				ans.push_back(a[a.size() - i - 1] - '0' + b[b.size() - 1 - i] - '0' + kuri - 10);
				kuri = 1;
			}
		}
		FOR(i, b.size(), a.size())
		{
			if (a[a.size()-i-1]-'0' + kuri < 10)
			{
				ans.push_back(a[a.size() - i - 1] - '0' + kuri);
				kuri = 0;
			}
			else
			{
				ans.push_back(a[a.size() - i - 1] - '0' + kuri-10);
				kuri = 1;
			}
		}
		if (kuri) ans.push_back(1);
		if (ans.size() > 80) cout << "overflow" << endl;
		else REP(i, ans.size()) cout << ans[ans.size()-1-i];
		cout << endl;
	}
	return 0;
}