def sort1d(arr):
  """
  Cet algo à une complexité de O(n log n)
  """

  if len(arr) < 2:
    return arr

  mid = len(arr) // 2
  left = sort1d(arr[:mid])
  right = sort1d(arr[mid:])

  result = []
  i = j = 0

  while i < len(left) and j < len(right):
    lv = left[i] if type(left[i]) is int else sum(left[i])
    rv = right[j] if type(right[j]) is int else sum(right[j])

    if lv < rv:
      result.append(left[i])
      i += 1
    else:
      result.append(right[j])
      j += 1

  result.extend(left[i:])
  result.extend(right[j:])
  return result

def sort2d(arr):
  """
  Cet algo à une complexité de O(m n log n + m log m)
  """

  sorted_rows = [sort1d(row) for row in arr]
  return sort1d(sorted_rows)