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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_special_scen_code(regions, emissions):
 """ Get special code for MAGICC6 SCEN files. At the top of every MAGICC6 and MAGICC5 SCEN file there is a two digit number. The first digit, the 'scenfile_region_code' tells MAGICC how many regions data is being provided for. The second digit, the 'scenfile_emissions_code', tells MAGICC which gases are in the SCEN file. The variables which are part of ``PART_OF_SCENFILE_WITH_EMISSIONS_CODE_1`` are the emissions species which are expected when scenfile_emissions_code is 1. Similarly, ``PART_OF_SCENFILE_WITH_EMISSIONS_CODE_0`` defines the emissions species which are expected when scenfile_emissions_code is 0. Having these definitions allows Pymagicc to check that the right set of emissions has been provided before writing SCEN files. Parameters region : list_like Regions to get code for. emissions : list-like Emissions to get code for. Raises ------ ValueError If the special scen code cannot be determined. Returns ------- int The special scen code for the regions-emissions combination provided. """

    if sorted(set(PART_OF_SCENFILE_WITH_EMISSIONS_CODE_0)) == sorted(set(emissions)):
        scenfile_emissions_code = 0
    elif sorted(set(PART_OF_SCENFILE_WITH_EMISSIONS_CODE_1)) == sorted(set(emissions)):
        scenfile_emissions_code = 1
    else:
        msg = "Could not determine scen special code for emissions {}".format(emissions)
        raise ValueError(msg)

    if set(regions) == set(["WORLD"]):
        scenfile_region_code = 1
    elif set(regions) == set(["WORLD", "OECD90", "REF", "ASIA", "ALM"]):
        scenfile_region_code = 2
    elif set(regions) == set(["WORLD", "R5OECD", "R5REF", "R5ASIA", "R5MAF", "R5LAM"]):
        scenfile_region_code = 3
    elif set(regions) == set(
        ["WORLD", "R5OECD", "R5REF", "R5ASIA", "R5MAF", "R5LAM", "BUNKERS"]
    ):
        scenfile_region_code = 4
    try:
        return scenfile_region_code * 10 + scenfile_emissions_code
    except NameError:
        msg = "Could not determine scen special code for regions {}".format(regions)
        raise ValueError(msg)