input: Write a python function to manage a circular linked list by implementing append, remove, and print_list methods.
  assert cll.print_list() == None  # Check that the list prints correctly.
  assert cll.append(10) == None  # Ensure appending elements works without errors.
  assert cll.append(20) == None
  assert cll.append(30) == None
  assert cll.remove(20) == None  # Ensure removal of elements works without errors.
  assert cll.remove(40) == "Element not found"  # Check removal of a non-existent element.
output: class Node:
      def __init__(self, data):
          self.data = data
          self.next = None
  
  class CircularLinkedList:
      def __init__(self):
          self.last = None
  
      def append(self, data):
          new_node = Node(data)
          if not self.last:
              self.last = new_node
              self.last.next = self.last
          else:
              new_node.next = self.last.next
              self.last.next = new_node
              self.last = new_node
  
      def remove(self, key):
          if not self.last:
              return "Element not found"
          
          curr = self.last.next
          prev = self.last
  
          while prev.next != self.last.next:
              if curr.data == key:
                  prev.next = curr.next
                  if curr == self.last:
                      self.last = prev
                  return
              prev = curr
              curr = curr.next
  
          if curr.data == key:
              if self.last == self.last.next:
                  self.last = None
              else:
                  prev.next = curr.next
                  self.last = prev
              return
  
          return "Element not found"
  
      def print_list(self):
          if not self.last:
              return
          curr = self.last.next
          while True:
              print(curr.data, end=" ")
              curr = curr.next
              if curr == self.last.next:
                  break
          print()
  ```
  
  The `CircularLinkedList` class includes:
  - An `append` method to add elements to the list.
  - A `remove` method to remove a specific element from the list.
  - A `print_list` method to print the elements in the list.