import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long tairyoku = Long.parseLong(sc.next());
		long kobetsuTairyoku = tairyoku;
		long count = 0;
		while(kobetsuTairyoku > 1) {
			kobetsuTairyoku = kobetsuTairyoku/2;
			count++;
		}
		long sumCount = 0;
		for(int i=0; i<=count; i++) {
			sumCount = (long) (sumCount + Math.pow(2, i));
		}
		System.out.println(sumCount);

	}

}
/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