import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String line = scanner.nextLine();
        String[] values = line.split(" ");
        long N = Long.parseLong(values[0]);
        if (N == 1) {
            System.out.println("1");
            return;
        }
        long temp = N;
        long atks = 0;
        long n = 0;
        while (temp >= 1) {
            temp = temp / 2;
            n += Math.pow(2,atks);
            atks ++;
        }
        System.out.println(n);
    }
}
/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