Remove Every Repeated Value

head is sorted in increasing order. Delete every node whose value appears more than once, so only values that were already distinct remain. For 1 -> 2 -> 3 -> 3 -> 4 -> 4 -> 5 the answer is 1 -> 2 -> 5.

The tests show a list as a Python list of its values: [1, 2, 3] stands for 1 -> 2 -> 3.

Examples

Example 1

Input:

remove_all_duplicates(head)  # head = 1 -> 2 -> 3 -> 3 -> 4 -> 4 -> 5

Output:

[1, 2, 5]

Example 2

Input:

remove_all_duplicates(head)  # head = 1 -> 1 -> 1 -> 2 -> 3

Output:

[2, 3]

Constraints

• 0 <= number of nodes <= 100000
• The list is sorted in increasing order.