def unique_elements_list_intersection(list1,list2):
    """
    Return the unique elements that are in both list1 and list2
    (repeated elements in listi will not be duplicated in the result).
    This should run in O(n1+n2) where n1=|list1|, n2=|list2|.
    """
    return list(set.intersection(set(list1),set(list2)))