




from math import factorial







def SCREAMING_SNAKE_CASE    (	lowercase_			,    lowercase_						)       ->	Optional[int]:



       """simple docstring"""

       if n < k or k < 0:
              raise ValueError('''Please enter positive integers for n and k where n >= k'''						)
       return factorial(_lowercase						) // (factorial(_lowercase						) * factorial(n - k						))


if __name__ == "__main__":
  print(
      """The number of five-card hands possible from a standard""",
      F'''fifty-two card deck is: {combinations(52, 5)}\n''',
  )

  print(
      """If a class of 40 students must be arranged into groups of""",
      F'''4 for group projects, there are {combinations(40, 4)} ways''',
      """to arrange them.\n""",
  )

  print(
      """If 10 teams are competing in a Formula One race, there""",
      F'''are {combinations(10, 3)} ways that first, second and''',
      """third place can be awarded.""",
  )








_lowerCamelCase     :		dict[str, float]								=       {
    "km/h": 1.0,
    "m/s": 3.6,
    "mph": 1.609_344,
    "knot": 1.852,
}

_lowerCamelCase     :		dict[str, float]								=       {
    "km/h": 1.0,
    "m/s": 0.277_777_778,
    "mph": 0.621_371_192,
    "knot": 0.539_956_803,
}







def SCREAMING_SNAKE_CASE    (	lowercase_			,    lowercase_			,    lowercase_						)       ->	float:



       """simple docstring"""

       if unit_to not in speed_chart or unit_from not in speed_chart_inverse:
              A__							=   (
                  f"""Incorrect 'from_type' or 'to_type' value: {unit_from!r}, {unit_to!r}\n"""
                  f"""Valid values are: {", ".join(lowercase_						)}"""
              )
              raise ValueError(lowercase_						)
       return round(speed * speed_chart[unit_from] * speed_chart_inverse[unit_to]			,    3						)


if __name__ == "__main__":
  import doctest

  doctest.testmod()


