Hint for RCE.py

Feeling stuck ?
Here is something for the 7x7 Programming Game!

This hint is for RCE.py and is as follows:

Perform context-aware input validation.
Check if input length is less than 17 characters and matches the IP regular expression ^((25[0-5]|(2[0-4]|1\d|[1-9]|)\d)\.?\b){4}$

All the best to those getting into the challenge series. Those who already blazed past, stay tuned for more!