input: Write a function to convert degrees Fahrenheit to degrees Celsius. The function should take in a temperature in Fahrenheit and return the equivalent temperature in Celsius.
  assert FahrenheitToCelsius(32) == 0.0
  assert FahrenheitToCelsius(212) == 100.0
  assert FahrenheitToCelsius(-40) == -40.0
  assert FahrenheitToCelsius(98.6) == 37.0
  assert FahrenheitToCelsius(0) == -17.77777777777778
  assert FahrenheitToCelsius(104) == 40.0
output: def FahrenheitToCelsius(fahrenheit):
      return (fahrenheit - 32) * 5 / 9