import java.util.*;

public class Main
{
	public static void main(String args[])
	{
		long a;
		long d=1;
		Scanner sc=new Scanner(System.in);
		a=sc.nextLong();
		while(a>1)
		{a=a/2;
			d*=2;}
			
		System.out.println(2*d-1);
	}
}
/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