#include <iostream>
#include <string>
#include <sstream>
using namespace std;
string toString(int n) {
    ostringstream os; os << n;
    return os.str();
}
string add(string a, string b) {
    if (a.size() > 80 || b.size() > 80) {
        return "overflow";
    }
    while (a.size() > b.size()) b = "0" + b;
    while (b.size() > a.size()) a = "0" + a;

    string res = "";
    int carry = 0;
    for (int i=a.size()-1; i>=0; --i) {
        int t = (a[i] - '0') + (b[i] - '0') + carry;
        res = toString(t % 10) + res;
        carry = t / 10;
    }
    if (carry) {
        res = "1" + res;
    }

    if (res.size() > 80) {
        return "overflow";
    }
    return res;
}
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n; cin >> n;
    string a, b;
    for (int i=0; i<n; ++i) {
        cin >> a >> b;
        cout << add(a, b) << endl;
    }
    return 0;
}