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

import java.util.Scanner;

class Fact1_N
{
	public static void main(String[] args)
	{
			Scanner input = new Scanner(System.in);

			int N = input.nextInt();
			int f = 1;

			int count = 1;
			while (count <= N)
			{
				f *= count;
				count ++;
			}

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