Given the head of a singly linked list, return the middle node of the linked list.
If there are two middle nodes, return the second middle node.
Example 1:
Input: 1 2 3 4 5 Output: 3 4 5
(Middle is node 3)
Example 2:
Input: 1 2 3 4 5 6 Output: 4 5 6
(Two middles: 3 and 4, return the second)
Constraints:
- The number of nodes in the list is in the range [1, 100]
Input format: Space-separated integers.
Output format: The middle node onwards.