ALL.MN CTF 2019 - Robots

Our team got 8th place of this competition.

We were annoyed by the slowness of the response of the server...

According to the title of the issue, I guess it relates to robots.txt.
I accessed http://chall.all.mn/robot/robots.txt, then I got following result.
********************************
User-agent: *
Disallow: /allmnflag.php
********************************

So I accessed http://chall.all.mn/robot/allmnflag.php, I got the flag.

The flag is: ALLMN{W3B_R0B0TS_TXT_7DHJ9E}