just feed your list to itertools.permutations and format accordingly in a list comprehension directly passing the tuple to format using the * operator.
import itertools
result = ["{}-{}".format(*x) for x in itertools.permutations([3, 8, 2],2)]
print(result)
result:
['3-8', '3-2', '8-3', '8-2', '2-3', '2-8']
As a side note, don't use input as a variable name as it overrides the interactive text input function.
