using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Please Write your Number : \n");

        int number = int.Parse(Console.ReadLine());

        long result = Fact(number);

        Console.WriteLine("Your Factourial is " + result ) ;

    }

    public static long Fact(int n){

        int f = 1;

        for(int i = 1;i<n+1 ;i++){

            f *=i;

        }

        return f ;

    }

}