// Read N from keybird and output 1*2* ...*N

import java.util.Scanner;

class Fact1_N_c
{
	public static void main(String[] args)
	{
			Scanner input = new Scanner(System.in);

			int N = input.nextInt();
			int f = N;

			while (N>1)
			{
				N--;
				f *= N;
			}

			System.out.println ("\nAnswer: " + f + "\n\n\n");
	}
}