class node:
    def __init__(self, pdata):
        self.data = pdata
        self.pointer = None

class linkedlist:
    def __init__(self):
        self.head = None

    def insertfront(self, pdata):
        newnode = node(pdata)
        if self.head is None:
            self.head = newnode
            return
        else:
            newnode.pointer = self.head
            self.head = newnode

    def insertindex(self, data, index):
        newnode = node(data)
        currentnode = self.head
        pos = 0
        if pos == index:
            self.insertfront(data)
        else:
            while (currentnode != None and pos+1 != index):
                pos+=1
                currentnode = currentnode.pointer

        if currentnode != None:
            newnode.pointer = currentnode.pointer
            currentnode.pointer = newnode
        else:
            print("index not present")

    def insertEnd(self, data):
        newnode = node(data)
        if self.head is None:
            self.insertfront(data)
            return
        else:
            currentnode = self.head
            while (currentnode.pointer):
                currentnode = currentnode.pointer

            currentnode.pointer = newnode


    def Output(self):
        currentnode = self.head
        while (currentnode.pointer != None):
            print(currentnode.data)
            currentnode = currentnode.pointer

        print(currentnode.data)

    def Delfront(self):
        if self.head == None:
            return
        else:
            self.head = self.head.pointer

    def Dellast(self):
        if self.head == None:
            return
        elif self.head.pointer == None:
            self.Delfront()
        else:
            currentnode = self.head
            while currentnode.pointer.pointer != None:
                currentnode = currentnode.pointer

            currentnode.pointer = None

    #def deleteatend(self):

print("af, means add to front of linked list\n"
      "al, means add to last of linked list\n"
      "ai, means add to index of linked list\n"
      "df, means delete from front of linked list\n"
      "dl, means delete from last of linked list\n"
      "di, means delete from index of linked list\n"
      "o, means output linked list\n")
x = ""
llist = linkedlist()
while x != "e":
    x = input("What do you want to do to the linked list\n>>>")
    if x == "af":
        y = input("Enter the data")
        llist.insertfront(y)
    elif x == "al":
        y = input("Enter the data")
        llist.insertEnd(y)
    elif x == "ai":
        y = input("Enter the data")
        index = int(input("Enter the index location"))
        llist.insertindex(y, index - 1)
    elif x == "df":
        llist.Delfront()
    elif x == "dl":
        llist.Dellast()
    elif x == "o":
        print("Llist is starting>")
        llist.Output()
        print("<Thats all folks")
    else:
        print("please input something appropriate")