# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:
    def deleteDuplicates(self, head):
        current = head

        while current and current.next:
            if current.val == current.next.val:
                # Skip the duplicate node
                current.next = current.next.next
            else:
                # Move forward only when values differ
                current = current.next

        return head