import java.util.Arrays;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Scanner;

public class Main {
	
	public static long solve(long n){
		if(n == 0){ 
			return 0;
		}else if(n == 1){
			return 0;
		}else if(n % 2 == 0){
			return (n / 2) + solve(n / 2);
		}else{
			return solve(n / 2) * 2;
		}
	}
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		final long N = sc.nextLong();
		
		System.out.println(solve(N));
	}
}