Xyene is going through a stressful week; It is yet another week of midterms, this time at university.

Unable to invest any more time into writing problems for the DMOPC, Xyene has offered you a position among the problemsetters of this DMCI-based contest, provided that you correctly answer the following skill-testing question:

Given an array ~A~ of integers, count the number of elements which share the parity of its index (~0~-based).

More colloquially, find the number of array elements which have the same remainder when divided by ~2~ (odd / even-ness) as its index.

Input Specification

The first line of the input contains the integer ~N~ ~(1 \le N \le 30)~, denoting the number of elements in the array ~A~.

The next line of the input contains ~N~ space-separated integers ~A_i~ ~(0 \le A_i \le 100)~, denoting the elements of the array ~A~.

Output Specification

Your program should output the number of array elements which have the same parity as its index on a single line by itself.

Sample Input

5
0 1 2 3 4

Sample Output

5

Explanation

$$\displaystyle A_0=0 \quad A_1 = 1 \quad A_2 = 2 \quad A_3 = 3 \quad A_4 = 4$$

All of the array elements are the same as their indices, so the answer is ~5~.