#!/usr/bin/env python3
import subprocess
import os
import re
import sys

def read_uid():
    os.environ['LIBNFC_DRIVER'] = 'pn532_i2c'
    os.environ['LIBNFC_DEVICE'] = 'pn532_i2c:/dev/i2c-1'
    
    try:
        result = subprocess.run(['nfc-list'], capture_output=True, text=True, timeout=5)
        if result.returncode == 0:
            match = re.search(r'UID\s*\(NFCID1\):\s*([0-9A-Fa-f\s]+)', result.stdout)
            if match:
                return match.group(1).strip().replace(' ', '').upper()
    except:
        pass
    return None

if __name__ == "__main__":
    uid = read_uid()
    print(uid if uid else "000000")