Remove Duplicates From a Sorted List

head is a list sorted in increasing order. Delete duplicates so that each value appears once and return the list.

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_duplicates_sorted(head)  # head = 1 -> 1 -> 2

Output:

[1, 2]

Example 2

Input:

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

Output:

[1, 2, 3]

Constraints

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