import java.util.*;

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