static int GetNthPrime(int n)
{
    List<int> primes = new List<int>() { 2, 3 };

    int potentialPrime = 5;

    while (primes.Count < n)
    {
        int squareRootPotentialPrime = (int)Math.Sqrt(potentialPrime);

        for (int i = 1; i < primes.Count; i++)
        {
            if (potentialPrime % primes[i] == 0)
            {
                break;
            }

            if (primes[i] > squareRootPotentialPrime)
            {
                primes.Add(potentialPrime);
                break;
            }
        }
        potentialPrime += primes[0];
    }

    return primes[n - 1];
}