• Why it wrong?

 

I would like to give some feedback about ...

From: https://py.checkio.org/mission/common-words/solve/

Your result: "one,two,three" Right result: "one,three,two" Fail: checkio(["one,two,three","four,five,one,two,six,three"]) My result is right. why('one,three,two') is right?