1 -> 2 ->3 -> 4 ------> 2
1 -> 2 -> 3 -> 2 -> null

class Node:
    def __init__(self,data=None,next=None):
        self.data=data
        self.next=next
class Linklist:
    def __init__(self):
        self.head=None 

    def add(self,data):
        newNode=Node(data)
        if(self.head):
            current=self



      


    
