using System.Linq;
using System.Collections.Generic;
using System;

class Eratosthenes
{
    public int[] Table;
    public Eratosthenes(int max)
    {
        CreateTable(max);
    }
    private void CreateTable(int n)
    {
        Table = Enumerable.Range(0, n + 1).ToArray();
        if (n <= 3) return;
        for (int i = 2; i <= n; i += 2) Table[i] = 2;
        for (int p = 3; p * p <= n; p += 2)
        {
            if (Table[p] < p) continue;
            for (int x = p; x <= n; x += p) Table[x] = p;
        }
    }
    public bool IsPrime(int n) => Table[n] == n;
    public int CountPrimes(int n)
    {
        var count = 0;
        while (Table[n] != 1)
        {
            n /= Table[n];
            count++;
        }
        return count;
    }
    public List<int> PrimeFactors(int n)
    {
        var res = new List<int>();
        while (Table[n] != 1)
        {
            res.Add(Table[n]);
            n /= Table[n];
        }
        return res;
    }
}

public class Hello
{
    static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        string[] line = Console.ReadLine().Trim().Split(' ');
        var a = Array.ConvertAll(line, int.Parse);
        getAns(n, a);
    }
    static void getAns(int n, int[] a)
    {
        if (n == 1) { Console.WriteLine(a[0] == 1 ? "black" : "white"); return; }
        var e = new Eratosthenes(1000000);
        var x = e.CountPrimes(a[0]) ^ e.CountPrimes(a[1]);
        for (int i = 2; i < n; i++) x ^= e.CountPrimes(a[i]);
        Console.WriteLine(x == 0 ? "black" : "white");
    }
}