def count_binary_trees(N):
  binary_size = [0]*(N+1)
  binary_size[1] = 1

  def count_binary(N):
    if N < 0:
      return 0
    if binary_size[N]:
      return binary_size[N]

    left_size, right_size = 1, N-2
    counter = 0
    while right_size > 0:
      counter += count_binary(left_size)*count_binary(right_size)
      left_size += 1
      right_size -= 1

    binary_size[N] = counter
    return  counter

  return count_binary(N)


print(count_binary_trees(11))