876. Middle of the Linked List

import math
class Solution:
    def middleNode(self, head):
        """
        :type head: ListNode
        :rtype: ListNode
        """
        n=0
        head1=head
        while head1:
            head1=head1.next
            n+=1
        for i in range(math.ceil(n/2)):
            head=head.next
        return head.val

class Solution(object):
    def middleNode(self, head):
        slow = fast = head
        while fast and fast.next:
            slow = slow.next
            fast = fast.next.next
        return slow

class Solution:
    def middleNode(self, head):
        """
        :type head: ListNode
        :rtype: ListNode
        """
        fast=slow=head
        while fast and fast.next:
            fast=fast.next.next
            slow=slow.next
        return slow