public int[] getSiblings(int[] arr, int x) {
    int pos = 0;
    for (int i = 0; i < arr.length; i++) {
      if(arr[i]==x) pos = i+1;
    }
    int start = Integer.highestOneBit(pos); // get max power of 2
    int end = start*2-1 >= arr.length ? arr.length: start*2-1;
    return IntStream.range(start-1, end).map(i -> arr[i]).filter(v -> v!=x).toArray();
  }