cs loop CATALAN Numbers (2n+1)!

using System;
using System.Numerics;

class CatalanNumbers
{
    static void Main()
    {
        byte n = byte.Parse(Console.ReadLine());
        BigInteger factorielN = 1, factoriel2N = 1, factorielNplus1 = 1;

        for (int i = 1; i <= n; i++)
            factorielN *= i;

        for (int i = 1; i <= (2 * n); i++)
            factoriel2N *= i;

        for (int i = 1; i <= (n + 1); i++)
            factorielNplus1 *= i;

        Console.WriteLine(factoriel2N / (factorielN * factorielNplus1));
    }
}