#include <iostream>
#include <vector>
#include <list>
#include <algorithm>
#include <string>
#include <stack>
#include <iomanip>
#include <numeric>
#include <queue>

using namespace std;
using ll = long long;
#define MOD 1000000007
#define INF 1LL << 59

int main()
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);

    int n;
    cin >> n;

    while (n--)
    {
        string s, t;
        cin >> s >> t;
        //cout << s << " " << t << endl;
        int carry = 0;
        string ans = "";
        while (!s.empty() || !t.empty())
        {
            int lastDigit_1 = (s.empty()) ? 0 : s.back() - '0';
            int lastDigit_2 = (t.empty()) ? 0 : t.back() - '0';

            int sum = lastDigit_1 + lastDigit_2 + carry;
            ans.push_back((char)('0' + sum % 10));
            carry = sum / 10;

            if (!s.empty())
                s.pop_back();
            if (!t.empty())
                t.pop_back();
        }

        if (carry)
            ans.push_back((char)('0' + carry));

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

        if (ans.size() > 80)
            cout << "overflow" << endl;
        else
            cout << ans << endl;
    }
    return 0;
}
