public class Test {
	public static int fact(int n) {
		if (n == 0 || n == 1) {
			return 1;
		}
		return n * fact(n - 1);
	}

	public static void main(String[] args) {
		int result = fact(5);
		System.out.println(result);
	}
}

/*
fact(5) = 5 * fact(4) = 120
fact(4) = 4 * fact(3) = 4 * 6 = 24
fact(3) = 3 * fact(2) = 3 * 2 = 6
fact(2) = 2 * fact(1) = 2 * 1 = 2
fact(1) = 1
 */