#include <iostream>
#include <string>
#include <sstream>
using namespace std;
string toStr(int n) {
    ostringstream os; os << n;
    return os.str();
}
string add(string a, string b) {
    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 = toStr(t % 10) + res;
        carry = t / 10;
    }
    if (carry) res = "1" + res;

    return (res.size() <= 80) ? res : "overflow";
}
int main() {
    int n; cin >> n;
    string a, b;
    while (n--) {
        cin >> a >> b;
        cout << add(a, b) << endl;
    }
    return 0;
}