import java.io.*;
import java.math.*;
import java.util.*;


public class Main {
	static int[] vy = {1,0,-1,0};
	static int[] vx = {0,1,0,-1};
	public static void main(String[] args) {	
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		long in = sc.nextLong();
		long sum = 0;
		long max = 0;
		while(in != 0) {
			max = Math.max(max, sum + in*2);
			sum += in;
			in /= 2;
		}
		System.out.println(max - sum);
	}
}