fn get_factors(n: usize) -> Vec<usize> {
    let mut ret = (0..=n).collect::<Vec<_>>();

    for i in 2..=(n as f64).sqrt().ceil() as usize {
        if ret[i] != i { continue; }
        for j in i..=n/i {
            ret[i*j] = i;
        }
    }

    ret
}

fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: usize = n.trim().parse().unwrap();
    let mut a = String::new();
    std::io::stdin().read_line(&mut a).ok();
    let a: Vec<usize> = a.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();

    let factors = get_factors(1000000);
    let mut factor_cnt = vec![0usize; 1000001];
    for i in 2..=1000000{
        if i == factors[i] {
            factor_cnt[i] = 1;
        } else {
            factor_cnt[i] = factor_cnt[i/factors[i]] + 1;
        }
    }
    let result = (0..n).map(|i| factor_cnt[a[i]]).filter(|&v| v > 0).fold(0usize, |x, y| x ^ y);
    if result == 0 {
        println!("black");
    } else {
        println!("white");
    }
}