using System;

​

public class Program

{

    public static void Main()

    {

        int x, result;

        Console.WriteLine("Informe o número:  ");

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

        result = x;

        //4 = 4 .3.2.1

            for(int n = 1; x!= n; n++){

               result = result * n;

            }

       Console.WriteLine(result);

    }

}