This one is already an accepted translation. Are you sure that everything else in your sentence was correct? No mixed up keyboards or anything like that? ^.^
You're welcome. If the problem remains, feel free to let us know and report the sentence. ^.^
Since this sentence discussion is a Greek-to-English translation exercise, if Artemios had to write Greek, I think it was a listening exercise -- and I don't think those can have multiple spellings unfortunately.
In a previous question i answered train as τραίνο was marked correct is there two spellings
Τρένο and τραίνο are both correct spellings, but in listening exercises, only one spelling can be accepted.