input: Write a function to convert degrees Fahrenheit to degrees Celsius. If the given temperature is 32 degrees Fahrenheit, the function should return 0 degrees Celsius. And if the given temperature is 212 degrees Fahrenheit, the function should return 100 degrees Celsius. If the input temperature is empty or not a number, the function should return "Invalid input". 
  
  def FahrenheitToCelsius(temp_fahrenheit):
      if not isinstance(temp_fahrenheit, (int, float)):
          return "Invalid input"
      temp_celsius = (temp_fahrenheit - 32) * 5/9
      return temp_celsius
  
  assert FahrenheitToCelsius(32) == 0
  assert FahrenheitToCelsius(212) == 100
  assert FahrenheitToCelsius("medium") == "Invalid input"
  assert FahrenheitToCelsius("") == "Invalid input"
output: def FahrenheitToCelsius(temp_fahrenheit):
      if not isinstance(temp_fahrenheit, (int, float)):
          return "Invalid input"
      temp_celsius = (temp_fahrenheit - 32) * 5/9
      return temp_celsius