import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        long N = Long.parseLong(sc.next());
        int count = 0;
        long x = N;
        long res = 0;
        while(x != 0){
            x /= 2;
            count++;
        }
        for(int i=0;i<count;i++){
            res += (long)Math.pow(2,i);
        }
        System.out.println(res);
    }
}
/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