import java.util.Scanner;

// D - Caracal vs Monster
// https://atcoder.jp/contests/abc153/tasks/abc153_d
public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        long H = Long.parseLong(scanner.next());
        scanner.close();

        System.out.println(f(H));
    }

    private static long f(long H) {
        if (H == 1) return 1;
        return f(H / 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