def quicksort(x):
    if not x:
        return []

    pivot = x[0]
    smaller = quicksort([a for a in x[1:] if a <= pivot])
    bigger = quicksort([a for a in x[1:] if a > pivot])

    return(smaller + [pivot] + bigger)


x = [10, 2, 5, 3, 1, 6, 7, 4, 2, 3, 4, 8, 9]
print(quicksort(x))