import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    final Scanner scanner = new Scanner(System.in);
    final long initialHitPoint = scanner.nextLong();

    System.out.println(getAttackCount(initialHitPoint));
  }

  private static long getAttackCount(long hitPoint) {
    if (hitPoint == 1) {
      return 1;
    }

    return getAttackCount(hitPoint / 2) * 2 + 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