#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
string a, b;

void calc() {
    if (a.size() > 80 || b.size() > 80) { cout << "overflow" << endl; return; }
    if (b.size() > a.size()) swap(a, b);
    int a1, b1, size1 = a.size()-1, size2 = b.size()-1, mod = 0, sum;
    while (size1 >= 0 && size2 >= 0) {
        a1 = a[size1] - '0';
        b1 = b[size2] - '0';
        sum = a1 + b1 + mod;
        mod = (sum > 9) ? 1 : 0; sum %= 10;
        a[size1] = (char) '0' + sum;
        size1--; size2--;
    }
    while (size1 >= 0 && mod > 0) {
        a1 = a[size1] - '0';
        sum = a1 + mod;
        mod = (sum > 9) ? 1 : 0; sum %= 10;
        a[size1] = (char) '0' + sum;
        size1--;
    }
    if (mod > 0) a = "1" + a;
    if (a.size() > 80) cout << "overflow" << endl;
    else cout << a << endl;
}


int main()  {
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> a >> b;
        calc();
    }

}

