import argparse
import fitz

def join_files(first_pdf, second_pdf, output_pdf):
    doc = fitz.open()
    doc.insert_file(first_pdf)
    doc.insert_file(second_pdf)
    doc.save(output_pdf)
    doc.close()

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Join two PDFs into a third PDF")
    parser.add_argument("first_pdf", help="Path to the first PDF file.")
    parser.add_argument("second_pdf", help="Path to the second PDF file.")
    parser.add_argument("output_pdf", help="Path to destination PDF file.")
    args = parser.parse_args()
    join_files(args.first_pdf, args.second_pdf, args.output_pdf)