Using .join()

[extricate]

Hi there,

I'm supposed to join up the string by entering an input. I can't seem to get it to work, I suspect the separator i input might not be a string. Any advice?

phrase_words = ['Jack', 'and', 'Jill', 'went', 'up', 'the', 'hill', 'To', 'fetch', 'a', 'pail', 'of', 'water']

separator = input("Enter: ")

print(separator.join(phrase_words))

Thanks