One of the conditions is that digits do not count. the prompt "Lorem ipsum dolor sit amet 0000000000000000000" is counting 0's as letters and saying that the correct answer (m) is incorrect.

I would like to give some feedback about ...

From: http://www.checkio.org/mission/most-wanted-letter/solve/

HTTP_USER_AGENT:

Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:32.0) Gecko/20100101 Firefox/32.0