import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long h = sc.nextLong();
		long sum = 0;
		long i = 1;

		if(h == 1) {
			System.out.println(1);
			System.exit(0);
		}

		do {
			h /= 2;
			sum += i;
			i *= 2;
		}while(h > 1);

		sum += i;

		System.out.println(sum);
		sc.close();
	}
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz