import json

def main():
    """
    Opens a HAR archive file "data.har" and prints a list of files (URLs)
    found in the archive.
    """
    har_file_path = "data.har"
    with open(har_file_path, 'r', encoding='utf-8') as f:
        har_data = json.load(f)

    entries = har_data.get('log', {}).get('entries', [])
    if not entries:
        print("No entries found in the HAR file.")
        return

    print("Files found in the HAR archive:")
    for entry in entries:
        request = entry.get('request', {})
        url = request.get('url')
        if url:
            print(url)
        else:
            print("Entry found with no request URL.")


if __name__ == "__main__":
    main()