input: Write a function to convert a given temperature value from Fahrenheit to Celsius. If the given temperature is below absolute zero (-459.67°F), return the message "Invalid temperature". Otherwise, return the temperature in Celsius rounded to two decimal places.
  def fahrenheit_to_celsius(temp):
      if temp < -459.67:
          return "Invalid temperature"
      celsius = (temp - 32) * 5/9 
      return round(celsius, 2)
  
  assert fahrenheit_to_celsius(32) == 0.0
  assert fahrenheit_to_celsius(212) == 100.0
  assert fahrenheit_to_celsius(-459.68) == "Invalid temperature"
  assert fahrenheit_to_celsius(-50) == -45.56
  assert fahrenheit_to_celsius(68) == 20.0
output: def fahrenheit_to_celsius(temp):
      if temp < -459.67:
          return "Invalid temperature"
      celsius = (temp - 32) * 5/9 
      return round(celsius, 2)