Given a Linked list of size N, the list is in alternating ascending and descending orders, your task is to complete the function sort() that sorts the given linked list in non-decreasing order.

Example:
Input List: 10->40->53->30->67->12->89->NULL
Output List: 10->12->30->40->53->67->89->NULL

Input:
The function takes a single argument as input the reference pointer to the head of the linked list.
There are T test cases and for each test case the function will be called separately.

Output:
For each test case function should return reference pointer to the head of the new linked list.

Constraints:
1<=T<=100
1<=N<=100
0<=A[]<=10³

Example:
Input:
2
6
1 9 2 8 3 7
5
13 99 21 80 50

Output:
1 2 3 7 8 9
13 21 50 80 99

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.

** For More Input/Output Examples Use 'Expected Output' option **