import java.util.*;

class Main {
    public static void main(String[] args) {
	Scanner scan = new Scanner(System.in);
        long n = scan.nextLong();
        if (n == 0) {
            System.out.println(0);
        } else {
            long lowestBit = Long.lowestOneBit(n);
            System.out.println(n / lowestBit * (lowestBit - 1));
        }
    }
}