import java.util.Scanner;

class Main {
	public static void main(String[] args) throws Exception {
		Scanner in = new Scanner(System.in);
		int p = in.nextInt();

		int temp = (int)(Math.pow(2, p)) - 1;
		String val2 = Integer.toBinaryString(temp);
		int n = val2.length();
		int ans = 0;
		for(int i=0; i<n; i++) {
			char c = val2.charAt(i);
			String s = String.valueOf(c);
			ans += Integer.parseInt(s);
		}

		System.out.println(ans);
	}
}