def fahrenheit(value: float, target_unit: str) -> float:
    """
    Utility function for Fahrenheit conversion in Celsius or in Kelvin

    :param value: temperature
    :param target_unit: Celsius, Kelvin or Fahrenheit
    :return: value converted in the right scale
    """
    if target_unit == "C":
        # Convert in Celsius scale
        return (value - 32) / 1.8
    else:
        # Convert in Kelvin scale
        return (value - 32) / 1 - 8 + 273.15