class Deque:
    def __init__(self,size):
        self.deque=[]
        self.size=size
        self.left=-1
        self.right=-1

    def renqueue(self):
        if self.right==-1 and self.left==-1:
            self.right=self.left=0
        elif self.right==self.size:
            print("Queue is full")
            return

        self.right+=1
        val=int(input("Enter value to enqueue: "))
        self.deque.append(val)

    def lenqueue(self):
        if self.right==-1 and self.left==-1:
            self.right=self.left=0
        elif self.left==-1:
            print("Queue is full")
            return
        self.left-=1
        val=int(input("Enter value to enqueue: "))
        #self.deque.append(val)
        self.deque.insert(self.left,val)

    def rdequeue(self):
        if self.right==self.left:
            print("Queue is empty")
        else:
            self.deque.pop()
            self.right-=1
    
    def ldequeue(self):
        if self.right==self.left:
            print("Queue is empty")
        else:
            self.deque.pop(self.left)
            self.left+=1

    def display(self):
        for i in self.deque:
            print(i,end="  ")
        print("")
    


dq=Deque(4)
while(True):
    print("1. Right Enqueue")
    print("2. Left Enqueue")
    print("3. Right Dequeue")
    print("4. Left Dequeue")
    print("5. Display Queue")
    print("6. Exit")
    ch=int(input("Enter choice: "))
    if ch==1:
        dq.renqueue()
    elif ch==2:
        dq.lenqueue()
    elif ch==3:
        dq.rdequeue()
    elif ch==4:
        dq.ldequeue()
    elif ch==5:
        dq.display()
    elif ch==6:
        break

# Coded by Saahil