func_code: def quicksort(l, beg, fin):
      if fin - beg < 1:
          return
      i = j = beg
      while i <= fin:
          if l[i] <= l[fin]:
              l[i], l[j] = l[j], l[i]
              j += 1
          i += 1
      quicksort(l, beg, j - 2)
      quicksort(l, j, fin)