Problem:
Score : 100 points

Problem Statement

AtCoDeer the deer found two positive integers, a and b.
Determine whether the product of a and b is even or odd.

Constraints

1 ≤ a,b ≤ 10000

a and b are integers.

Input

Input is given from Standard Input in the following format:

a b

Output

If the product is odd, print Odd; if it is even, print Even.

Sample Input 1

3 4

Sample Output 1

Even

As 3 × 4 = 12 is even, print Even.

Sample Input 2

1 21

Sample Output 2

Odd

As 1 × 21 = 21 is odd, print Odd.

Solution in Rust (1.15.1) (judge verdict: Accepted)

// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let mut s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};

    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };

    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };

    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };

    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };

    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}

fn main() {
    input! {
        a: isize,
        b: isize
    }
    let ans = if a * b % 2 == 0 { "Even" } else { "Odd" };
    println!("{}", ans);
}