Description

Given a Linked List, separate the nodes at odd positions from the nodes at even positions. Print the nodes at odd positions first, followed by the nodes at even positions.

給一個Linked List，請把奇數位置的node與偶數位置的node分開後，先印出奇數位置node後，再印出偶數位置的node

For example: 1 -> 2 -> 5 -> 7 -> 10 -> 3

例如：1 -> 2 -> 5 -> 7 -> 10 -> 3

The output should be: 1 -> 5 -> 10 -> 2 -> 7 -> 3

則答案應該輸出：1 -> 5 -> 10 -> 2 -> 7 -> 3

**請使用Linked List撰寫!!**我會檢查，用array不予採計。

Input

The input consists of a sequence of numbers, terminated by -1.

輸入包含一串數列，以 -1 結束。

Output

First, print the nodes at odd positions, followed by the nodes at even positions.

請先印出奇數位置的節點，再印出偶數位置的節點。

Sample Input 1

1 2 5 7 10 3 -1

Sample Output 1

1->5->10->2->7->3