import math


def calculate_fuel_requirement_plus(fuel):
    """Calculates the fuel requirement
    based on the given fuel mass. (Part 2)

    Parameters:
    fuel (int): mass of the fuel

    Returns:
    int:Additional fuel required

    """
    add = math.floor(fuel / 3) - 2 
    if add > 0:
        return add + calculate_fuel_requirement_plus(add)
    else:
        return 0