Slicing odd places

You will be given a linked list and you are asked to remove nodes which are positioned at odd places. Node 1 is indexed at position 1.

Input Format

You will be given N representing the length of the linked list. Below N lines will have data for specific node.

Constraint

1 <= N <= 10

Sample TestCase 1

Input

6

2

3

4

5

6

7

Output

3

5

7

Sample TestCase2

Input

12

2

3

4

5

6

7

1

8

9

0

11

14

Output

0