import math


def calc_module_fuel(mass):
    """
    This function recursively returns the fuel needed including the additional
    fuel required for the fuel mass
    """
    fuel = math.trunc(mass / 3) - 2
    # Base case
    if fuel < 1:
        return 0

    else:
        # calculate initial fuel
        fuel = math.trunc(mass / 3) - 2
        # recursively calculate total fuel for this module
        return fuel + calc_module_fuel(fuel)