#!/usr/bin/env python

from poplib import POP3
import sys


#POP server against which we authenticate
server="127.0.0.1"
#Port number for POP server. Usually 110
port=110


#Below here you shouldn't need to edit anything

while 1:

	#Read user and password from stdin, remove the newline, split at the space
	#and assign to the user and password variables

	line=sys.stdin.readline()[:-1]
	[user,password]=line.split(' ')

	#Connect to the POP server

	p=POP3(server,port)

	#Try to authenticate. If it doesn't work, it throws an exception

	try:
		p.user(user)
		p.pass_(password)
	except:

		#If it threw an exception, log in cache.log the ayth booboo
		sys.stderr.write("ERR authenticating %s\n"%user)
		#Then deny access
		sys.stdout.write("ERR\n")
		#IMPORTANT!!!!!!!!!!!! Flush stdout
		sys.stdout.flush()
		continue

	#If it didn't throw exceptions, that means it authenticated

	#Log success to cache.log
	sys.stderr.write("OK authenticated %s\n"%user)
	#Then allow access
	sys.stdout.write("OK\n")
	sys.stdout.flush()