#include <iostream>
#include <string>

using namespace std;

int main()
{
    int num;

    cin >> num;
    for (int i = 0; i < num; i++) {
        string s1, s2;

        cin >> s1 >> s2;
        if (s1.size() > 80 || s2.size() > 80)
            cout << "overflow" << endl;
        else {
            int i1 = s1.size();
            int i2 = s2.size();
            string ans;
            int tmp = 0;
            int up = 0;

            for ( ; (i1 > 0) && (i2 > 0); i1--, i2-- ) {
                tmp = (s1[i1 - 1] + s2[i2 - 1]) - 2 * '0' + up;
                up = tmp / 10;
                tmp %= 10;
                ans = char(tmp + '0') + ans;
            }
            
            if (i1 > 0) {
                for ( ; i1 > 0; i1--) {
                    tmp = s1[i1 - 1] - '0' + up;
                    up = tmp / 10;
                    tmp %= 10;
                    ans = char(tmp + '0') + ans;
                }
            }
            else if (i2 > 0) {
                for ( ; i2 > 0; i2--) {
                    tmp = s2[i2 - 1] - '0' + up;
                    up = tmp / 10;
                    tmp %= 10;
                    ans = char(tmp + '0') + ans;
                }
            }

            if (up > 0)
                ans = char(up + '0') + ans;
            cout << ans << endl;
        }
    }

    return 0;
}