#separation of linked list alternatively
class Node:
    def __init__(self,data):
        self.data=data
        self.next=None

cur=root=Node(-1)
#creeate linked list
for i in [2,99,55,77,8]:
    cur.next=Node(i)
    cur=cur.next
root=root.next

def display(x):
    while x!=None:
        print(x.data,end=" ")
        x=x.next
    print()

def separate(root):
    odd_head  = odd  = Node(-1)
    even_head = even = Node(-1)

    flag=True

    cur=root

    while cur!=None:
        if flag==True:
            even.next=cur
            even=even.next
            flag=False
        else:
            odd.next=cur
            odd=odd.next
            flag=True

        cur=cur.next

    odd.next=None
    even.next=None
    return odd_head.next,even_head.next

display(root)
odd_head,even_head=separate(root)
display(odd_head)
display(even_head)