import java.util.*;
public class Main
{
  public static void main(String args[])
  {
    Scanner sc = new Scanner(System.in);
    long n = sc.nextLong();
    long t = (long)Math.floor(Math.log(2*n)/Math.log(2));
    t = (long)Math.pow(2,t);
    System.out.println(t-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