// @nuget: CommandLineParser -Version 2.7.82

using System;

​

public class Program

{

    public static void Main()

    {

        var p = 5;

        var test = ((Factorial(p - 1) + 1) / (p * p));

        Console.WriteLine(test);

    }

    public static int Factorial(int x) => 

        x == 1 ? x : x * Factorial(x - 1);

}