I am trying to get a unique random number but i always get the same number every time i run the code. i will get 14 first then 6 but my list for holding all the used numbers doesn't seem to work.adding the 14 manually works but when i add randInt it doesn't work.

```
const int numCards = 32;
        List<int> usedCards = new List<int>();
        int randInt = 0;
        Random rand = new Random(numCards);
        usedCards.Add(14);
        do
        {

            randInt = rand.Next(0, numCards);
            MessageBox.Show(randInt.ToString(), "End Game", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);

        }
        while (usedCards.Contains(randInt));

        usedCards.Add(randInt);

```