using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Введите число");

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

        int[] fact = new int[64];

        int i = 0;

        int symfact = 1;

        while(i<=number)

        {

            fact[i] = i;

            i++;

        }

        i = 1;

        while(i<=number)

        {

            symfact *= fact[i];

            i++;

        }

        Console.WriteLine(symfact);

​

    }

}