class Node {
public:
    Node *prev;
    int data;
    Node *next;
 
    Node(int value) {
        prev = nullptr;
        data = value;
        next = nullptr;
    }
};
 
class Circular_Doubly_Linked_List {
private:
    Node *start;
 
public:
    Circular_Doubly_Linked_List() {
        start = nullptr;
    }
};

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None
        self.prev = None
 
 
class Circular_Doubly_Linked_List:
    def __init__(self) -> None:
        self.start = None

void insert_beginning(int value) {
    Node *new_node = new Node(value);
    if (start == nullptr) {
        start = new_node;
        new_node->next = new_node;
        new_node->prev = new_node;
        return;
    }
    new_node->next = start;
    new_node->prev = start->prev;
    start->prev->next = new_node;
    start->prev = new_node;
    start = new_node;
    return;
}

def insertBeginning(self, value):
    newNode = Node(value)
    if self.start is None:
        self.start = newNode
        newNode.next = newNode
        newNode.prev = newNode
    else:
        newNode.next = self.start
        newNode.prev = self.start.prev
        self.start.prev.next = newNode
        self.start.prev = newNode
        self.start = newNode

void insert_end(int value) {
    Node *new_node = new Node(value);
    if (start == nullptr) {
        start = new_node;
        new_node->next = new_node;
        new_node->prev = new_node;
        return;
    }
    Node *ptr = start;
    while (ptr->next != start)
        ptr = ptr->next;
 
    ptr->next->prev = new_node;
    new_node->next = ptr->next;
    new_node->prev = ptr;
    ptr->next = new_node;
}

def insertEnd(self, value):
    newNode = Node(value)
    if self.start is None:
        self.start = newNode
        newNode.next = newNode
        newNode.prev = newNode
    else:
        ptr = self.start
        while ptr.next != self.start:
            ptr = ptr.next
 
        ptr.next.prev = newNode
        newNode.next = ptr.next
        newNode.prev = ptr
        ptr.next = newNode

void delete_beginning() {
    if (start == nullptr) {
        cout << "List is empty" << endl;
        return;
    }
    if (start->next == start) {
        delete start;
        start = nullptr;
        return;
    }
    Node *ptr = start;
    start->prev->next = start->next;
    start->next->prev = start->prev;
    start = start->next;
    delete ptr;
    return;
}

def deleteBeginning(self):
    if self.start is None:
        print("The Linked List is Empty!")
        return
    elif self.start.next == self.start:
        self.start = None
    else:
        self.start.next.prev = self.start.prev
        self.start.prev.next = self.start.next
        self.start = self.start.next

void delete_end() {
    if (start == nullptr) {
        cout << "List is empty" << endl;
        return;
    }
    if (start->next == start) {
        delete start;
        start = nullptr;
        return;
    }
    Node *ptr = start;
    while (ptr->next != start)
        ptr = ptr->next;
 
    ptr->prev->next = start;
    start->prev = ptr->prev;
    delete ptr;
    return;
}

def deleteEnd(self):
    if self.start is None:
        print("The Linked List is Empty!")
        return
    elif self.start.next == self.start:
        self.start = None
    else:
        ptr = self.start
        while ptr.next != self.start:
            ptr = ptr.next
 
        ptr.prev.next = ptr.next
        ptr.next.prev = ptr.prev

def display(self):
    if self.start is None:
        print("The Linked List is Empty!")
        return
    else:
        print('The Linked List is: ', end="")
        ptr = self.start
        while ptr.next != self.start:
            print(ptr.data, end=" ")
            ptr = ptr.next
        print(ptr.data)