import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        // ABC153D - Caracal vs Monster

        Scanner sc = new Scanner(System.in);

        long h = sc.nextLong();

        if (h == 1) {
            System.out.println(1);
            return;
        }
        
        long x = h;
        int cnt = 0;
        while(true) {
            x /=2;
            cnt++;
            if (x == 1) break;
        }
        
        long ans = 2;
        for (int i = 0; i < cnt; i++) {
            ans *= 2;
        }
        
        if (cnt > 0) ans--;

        System.out.println(ans);
    }

}
/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