Factorial

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {

            int n = int.Parse(Console.ReadLine());
            int fact = 1;
            do
            {
                fact = fact * n;
                n--;
            }
            while (n > 1);
            Console.WriteLine(fact);


        }
    }
}