using System;
using System.IO;
using System.Linq;
using System.Collections.Generic;

public class Program
{

	public void Proc()
	{
        long inpt = long.Parse(Reader.ReadLine());
        long ans = 1;
        long mod = 1000000000000;
        for (int i = 1; i <= inpt; i++) {
            ans = ans * i;
            ans = ans % mod;
            if(ans == 0) {
                break;
            }
        }
        string strAns = ans.ToString("000000000000");
        if(inpt < 50) {
            strAns = ans.ToString();
        }
        Console.WriteLine(strAns);
    }

	public class Reader
	{
		private static StringReader sr;
		public static bool IsDebug = false;
		public static string ReadLine()
		{
			if (IsDebug)
			{
				if (sr == null)
				{
					sr = new StringReader(InputText.Trim());
				}
				return sr.ReadLine();
			}
			else
			{
				return Console.ReadLine();
			}
		}
		private static string InputText = @"



50


";
	}

	public static void Main(string[] args)
	{
#if DEBUG
		Reader.IsDebug = true;
#endif
		Program prg = new Program();
		prg.Proc();
	}
}