def parseArgs():
    parser = argparse.ArgumentParser()
    parser.add_argument("cg1", help="This is the first .CGX (CommonGraph) file")
    parser.add_argument("cg2", help="This is the second .CGX (CommonGraph) file")
    parser.add_argument("ds", help="This is the output filename of a .DSX (DiffSet) file")
    return parser.parse_args()