Given a single linkd list of size M, your task is to complete the function sumOfLastN_Nodes(), which should return the sum of last N nodes of the linked list.
The function takes two arguments as input, the reference pointer to the head of the linked list and the an integer N.
There will be T test cases and for each test case the function will be called seperately.
For each test case output the sum of last N nodes of the linked list.
5 9 6 3 4 10
Note:The Input/Ouput format and Example given are used for system's internal purpose, and should be used by a user for Expected Output only. As it is a function problem, hence a user should not read any input from stdin/console. The task is to complete the function specified, and not to write the full code.