#include <iostream>
#include <string>

using namespace std;

int main() {
    int N;
    cin >> N;
    for (int i=0; i<N; i++) {
        string a, b, c;
        cin >> a >> b;
        int sum, ret=0;
        if (a.length() < b.length()) swap(a,b);
        int l = b.length()-1;
        for (int i=a.length()-1; i>=0; i--) {
            if (l >= 0) {
                sum = (a[i]-'0')+(b[l]-'0')+ret;
                l--;
            } else {
                sum = (a[i]-'0')+ret;
            }
            if (sum>=10) {
                ret = 1;
                sum -= 10;
            } else {
                ret = 0;
            }
            c[i] = sum+'0';
        }
        if (ret != 0) {
            c.insert(a.begin(), ret+'0');
        }
        if (c.length() > 80) cout << "overflow" << endl;
        else cout << c << endl;
    }
    return 0;
}