class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

def deleteDuplicates(head: ListNode) -> ListNode:
    current = head
    while current and current.next:
        if current.val == current.next.val:
            current.next = current.next.next
        else:
            current = current.next
    return head

def list_to_linkedlist(lst):
    if not lst:
        return None
    head = ListNode(lst[0])
    current = head
    for value in lst[1:]:
        current.next = ListNode(value)
        current = current.next
    return head

def linkedlist_to_list(head):
    result = []
    while head:
        result.append(head.val)
        head = head.next
    return result

lst = [1, 1, 2, 3, 3]
head = list_to_linkedlist(lst)
new_head = deleteDuplicates(head)
result = linkedlist_to_list(new_head)
print(result)