#include <iostream>
using namespace std;
int main()
{
    int v;
    cin >> v;
        for (int z = 0; z < v; z++)
        {
                int x, y, k, t, c = 0, i = 0, b;
                cin >> x >> y >> k >> t;
                while (i <= t && c < k)
                {
                        b = x;
                        while (1)
                        {
                                if (b >= x && b % y == 0)
                                {
                                        x = b;
                                        break;
                                }
                                else
                                        b++;
                        }
                c++;
                i++;
                }
        cout << x << endl;
        }
return 0;
}