import java.util.*;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long h = sc.nextLong();
		long x=0;
		int count=0;
		while(h>0) {
			h/=2;
			count++;
		}
		for(int i=0;i<count;i++) {
			x+=Math.pow(2, i);
		}

		  		System.out.print(x);

	}
}
/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