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

namespace yukicoder
{
	class pg
	{
		static void Main(string[] args)
		{
			long N = long.Parse(Console.ReadLine());
			long ans = 1;
			long mod = 1000000000000;
			
			bool modSwitch = false;
			
			for(long i = 1;i <= N;i++)
			{
				ans *= i;
				
				if(ans > mod)
				{
					modSwitch = true;
					ans %= mod;
				}
				if(ans == 0)
				{
					Console.WriteLine("000000000000");
					return;
				}
			}
			
			if(modSwitch)
			{
				Console.WriteLine(ans.ToString("d12"));
			}else
			{
				Console.WriteLine(ans);
			}
			
		}
	}
}