import java.util.Scanner;


public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long M_hp = sc.nextLong();
		long count = 1;
		long attack = 1;
		int flg = 0;
		if(M_hp == 1) {
		}else {

			for(;;) {
				M_hp = M_hp/2;
				if(M_hp < 2) {
					count = count*2;
					attack = attack + count;
					break;
				}else {
					count = count*2;
					attack = attack + count;
				}

			}
		}
			System.out.println(attack);
		}
	}

/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