#![allow(unused_imports)]
#![allow(non_snake_case, unused)]

// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        input_inner!{next, $($r)*}
    };
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes
                .by_ref()
                .map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

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

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

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

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

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

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

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

use std::io::Write;
use std::collections::*;
use std::cmp::*;
use std::ops::*;
use std::marker::*;

const INF: i64 = std::i64::MAX/100;
const MOD: i64 = 1_000_000_007;
// const MOD: i64 = 998244353;

struct SieveOfEratosthenes {
    primes: Vec<usize>,
    divs: Vec<usize>,
}

impl SieveOfEratosthenes {
    pub fn new(n: usize) -> Self {
        let mut divs = vec![1;n+1];
        for i in 2..=n {
            if divs[i]!=1 {
                continue;
            }
            for j in 1..=n {
                let val = i*j;
                if val>n {
                    break;
                }
                divs[val as usize] = i;
            }
        }
        let mut primes = divs.iter()
                             .enumerate()
                             .filter(|x| *x.1>1 && x.0==*x.1)
                             .map(|x| *x.1)
                             .collect::<Vec<usize>>();
        SieveOfEratosthenes {
            divs,
            primes,
        }
    }
    pub fn factors(&self, n: usize) -> Vec<(usize,usize)> {
        assert!(n+1<=self.divs.len());
        let mut ans = vec![];
        let mut x = n;
        while x > 1 {
            let nxt = self.divs[x];
            ans.push(nxt);
            x /= nxt;
        }
        let mut map = HashMap::<usize,usize>::new();
        for &a in &ans {
            *map.entry(a).or_insert(0) += 1;
        }
        let mut ret = vec![];
        for (&k,&v) in map.iter() {
            ret.push((k,v));
        }
        ret
    }
}

fn main() {
    input! {
        n: (i64),
        a: [usize;n],
    }
    let mut p = SieveOfEratosthenes::new(1000001);
    let mut x = 0;
    for &a in &a {
        let q = p.factors(a);
        let mut sum = 0;
        for (_,y) in &q {
            sum += y;
        }
        x ^= sum;
    }
    if x==0 {
        println!("black");
    }
    else {
        println!("white");
    }
}