import java.util.Arrays;
import java.util.Scanner;
public class Main{
	public static void main(String[]args) {
		Scanner sc=new Scanner(System.in);
		long n=sc.nextLong();
		long c=1;
		long sum=0;
		while(n!=0) {
			n=n/2;
			sum=sum+c;
			c=c*2;
		}
		System.out.println(sum);  
		
	}
	
}
/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