// Mason Marnell -  Factorial 
import static java.lang.System.in;

import java.util.Scanner;

public class SumOfDigits {
		
		public static int sumDigits(int num){
			if(num <= 1) return num;
			return sumDigits(num-1) * num;
			
		}
	

	public static void main(String[] args) {
		 Scanner keyb = new Scanner(in);
	        System.out.println("Enter a factorial (without the !)");
	        int nm = keyb.nextInt();
		System.out.println(sumDigits(nm));

	}

}