# Creating the linked list class and the function to remove duplicates
class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

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

# Helper function to convert list to linked list
def create_linked_list(arr):
    if not arr:
        return None
    head = ListNode(arr[0])
    current = head
    for val in arr[1:]:
        current.next = ListNode(val)
        current = current.next
    return head

# Helper function to convert linked list to list (for easier display)
def linked_list_to_list(head):
    result = []
    current = head
    while current:
        result.append(current.val)
        current = current.next
    return result

# Test case
input_data = [1, 1, 2, 3, 3]
linked_list = create_linked_list(input_data)
result = deleteDuplicates(linked_list)
output_data = linked_list_to_list(result)
print(output_data)