"""
In each input list, every number repeats at least once, except for two.
Write a function that returns the two unique numbers.
Examples:
returnUnique([1, 9, 8, 8, 7, 6, 1, 6]) ➞ [9, 7]
returnUnique([5, 5, 2, 4, 4, 4, 9, 9, 9, 1]) ➞ [2, 1]
returnUnique([9, 5, 6, 8, 7, 7, 1, 1, 1, 1, 1, 9, 8]) ➞ [5, 6]
"""
