• COMMON WORDS SOLVE not working

 

I would like to give some feedback about COMMON WORDS SOLVE

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

Though the folloing code works in the try section and in local PYthn the console throughs an error saying SET is not a date type

def checkio(first, second): a = first.split(",") b = second.split(",") a1 = set(a) b1 = set(b) result = a1.intersection(b1) return result