Problem Setter: Marajul islam

BSMRSTU CSE 3rd year

In every year, an International regional programming contest called ICPC is arranged. Every reputed university from Bangladesh take part in this event. This is not an individual contest. This is a team contest. Each team has 3 members and a coach. Like every university BSMRSTU have took part in this event. Last year four team participated in ICPC . Team named are BSMRSTU_once_again, BSMRSTU_night_coder, BSMRSTU_D3PRIV3D and BSMRSTU_Begginer_Legend.

However, in this year every team consist of 3 member. And this year our respected Sheikh Monir ,and Ahasanur Rahman vaiya can’t take part ICPC any more as they already graduated . Of course, we will miss them. But we have to form new team. Therefore, this year forming a team for ICPC create a problem.

Members of programming club go to Akkas ali sir, chairman of CSE department to get solution for this problem. He told that 3 members can form a team if their sum of rating is even.

As you are a great programmer so club give, you this problem given each member rating Ri you have to determine how many ways you can form a team.

Input Format

First line contains an integer number N denoting number of member in BSMRSTU Programming club. Next line contains N integer denoting Rating of i_th member R_i.

Constraints

3 <= N <= 10^5

1 <= R_i <= 10^5

Output Format

Print One integer that how many ways you can form a team.

Samples

Explanation:

Look it can be form team like this (1,2,3) , (1,3,4) = 2 ways