from math import factorial



def 			__SCREAMING_SNAKE_CASE						(      __UpperCamelCase					: int = 20			)							->      int:







  """simple docstring"""





  SCREAMING_SNAKE_CASE__    							=   2 * n  # middle entry of odd rows starting at row 3 is the solution for n = 1,
  # 2, 3,...
  SCREAMING_SNAKE_CASE__    							=   n // 2

  return int(factorial(__UpperCamelCase			) / (factorial(__UpperCamelCase			) * factorial(n - k			))			)


if __name__ == "__main__":
   import sys

   if len(sys.argv) == 1:
      print(solution(20))
   else:
      try:
         __lowerCamelCase    :				int							     =	int(sys.argv[1])
         print(solution(n))
      except ValueError:
         print('''Invalid entry - please enter a number.''')

from math import isqrt



def 			__SCREAMING_SNAKE_CASE						(      __UpperCamelCase					: int			)							->      bool:







  """simple docstring"""





  return all(number % divisor != 0 for divisor in range(2				,  isqrt(__UpperCamelCase			) + 1			)			)



def 			__SCREAMING_SNAKE_CASE						(      __UpperCamelCase					: int = 10**6			)							->      int:







  """simple docstring"""





  SCREAMING_SNAKE_CASE__    							=   0
  SCREAMING_SNAKE_CASE__    							=   1
  SCREAMING_SNAKE_CASE__    							=   7
  while prime_candidate < max_prime:
    primes_count += is_prime(__UpperCamelCase			)

    cube_index += 1
    prime_candidate += 6 * cube_index

  return primes_count


if __name__ == "__main__":
   print(F"""{solution() = }""")
