#include <iostream>
#include <string>
#include <algorithm>
using namespace std;

string tasu(string& a, string& b) {
    string s = "";
    if (a.size() < b.size()) swap(a, b);
    int prev = 0;
    for (int i = 1; i <= a.size(); i++) {
        int ac, bc, sum;
        ac = a[a.size()-i] - '0';
        if (b.size() < i) {
            bc = 0;
        } else {
            bc = b[b.size() - i] - '0';
        }
        sum = ac + bc + prev;
        prev = 0;
        if (sum >= 10) {
            prev = 1;
            sum -= 10;
        }
        s.push_back(sum + '0');
    }
    if (prev) s.push_back('1');
    reverse(s.begin(), s.end());
    if (s.size() > 80) s = "overflow";
    return s;
}

int main() {
    int N; cin >> N;
    for (int i = 0; i < N; i++) {
        string a, b;
        cin >> a >> b;
        cout << tasu(a, b) << endl;
    }
    return 0;
}