import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    // TODO 自動生成されたメソッド・スタブ
    Scanner sc = new Scanner(System.in);

    long h = sc.nextLong();

    if (h == 1) {
      System.out.println(1);
      return;
    }
    // n段のピラミッド
    long cnt = 1;
    while (h / 2 > 1) {
      h = h / 2;
      cnt++;
    }

    Double d = 0d;
    for (long i = 0; i < cnt + 1; i++) {
      d += Math.pow(2, i);
    }
    System.out.println(d.longValue());
  }
}

/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