Problem:
Score : 200 points

Problem Statement

We have N squares assigned the numbers 1,2,3,\ldots,N. Each square has an integer written on it, and the integer written on Square i is a_i.

How many squares i satisfy both of the following conditions?

The assigned number, i, is odd.

The written integer is odd.

Constraints

All values in input are integers.

1 \leq N, a_i \leq 100

Input

Input is given from Standard Input in the following format:

N
a_1 a_2 \cdots a_N

Output

Print the number of squares that satisfy both of the conditions.

Sample Input 1

5
1 3 4 5 7

Sample Output 1

2

Two squares, Square 1 and 5, satisfy both of the conditions.

For Square 2 and 4, the assigned numbers are not odd.

For Square 3, the written integer is not odd.

Sample Input 2

15
13 76 46 15 50 98 93 77 31 43 84 90 6 24 14

Sample Output 2

3

Solution in Rust (1.42.0) (judge verdict: Accepted)

use input::Input;

fn main() {
    let mut input = Input::default();

    let n = input.parse();
    let a = (0..n).map(|_| input.parse::<u32>()).collect::<Vec<_>>();

    let mut cnt = 0;
    for (i, x) in a.iter().enumerate() {
        if i % 2 == 0 && x % 2 != 0 {
            cnt += 1;
        }
    }

    println!("{}", cnt);
}

#[allow(dead_code)]
pub mod input {
    #[derive(Default)]
    pub struct Input(Vec<String>);

    impl Input {
        pub fn read_line(&mut self) -> String {
            let mut s = String::new();
            std::io::stdin().read_line(&mut s).ok().expect("read error");
            s
        }
        pub fn parse<T: std::str::FromStr>(&mut self) -> T {
            let x = if let Some(x) = self.0.pop() {
                x
            } else {
                let s = self.read_line();
                self.0 = s.split_whitespace().map(String::from).rev().collect();
                self.0.pop().expect("reached EOF")
            };
            x.parse().ok().expect("parse error")
        }
    }
}