Something might be broken

Hello there,

I tried to submit a solution for "the longest palindromic" mission. When I run it, it says that I've failed on checkio("abc") because it expected "a" as the right answer. I don't get how "a" would be palindromic.

From: https://checkio.org/mission/the-longest-palindromic/solve/

HTTP_USER_AGENT:

Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36