[백준 10872]팩토리얼

import java.util.Scanner;

public class Main {
	public static int factorial(int n) {
		if(n<=1) {
			return 1;
		}
		return n*factorial(n-1);
	}
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int n= in.nextInt();
		System.out.println(factorial(n));
	}
}