Given a linked list consisting of L nodes and given a number N. The task is to find the N^th node from the end of the linked list.

Example 1:

Input:
N = 2
LinkedList: 1->2->3->4->5->6->7->8->9
Output: 8
Explanation: In the first example, there
are 9 nodes in linked list and we need
to find 2nd node from end. 2nd node
from end os 8.  

Example 2:

Input:
N = 5
LinkedList: 10->5->100->5
Output: -1
Explanation: In the second example, there
are 4 nodes in the linked list and we
need to find 5th from the end. Since 'n'
is more than the number of nodes in the
linked list, the output is -1.

Your Task:
The task is to complete the function getNthFromLast() which takes two arguments: reference to head and N and you need to return N^th from the end or -1 in case node doesn't exist..

Note:
Try to solve in single traversal.

Expected Time Complexity: O(N).
Expected Auxiliary Space: O(1).

Constraints:
1 <= L <= 10⁶
1 <= N <= 10⁶