using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var a = NList;
        var mlist = GetMinPDivList(a.Max());
        var ans = 0;
        foreach (var ai in a)
        {
            if (ai > 1) ans ^= PDiv(ai, mlist).Count;
        }
        WriteLine(ans == 0 ? "black" : "white");
    }
    static int[] GetMinPDivList(int max)
    {
        var minPDivList = new int[max + 1];
        for (var i = 0; i <= max; ++i) minPDivList[i] = i;

        for (var i = 2; i * i <= max; ++i) if (minPDivList[i] == i)
        {
            for (var j = i * i; j <= max; j += i) if (minPDivList[j] == j)
            {
                minPDivList[j] = i;
            }
        }
        return minPDivList;
    }
    static int GetMinPDiv(int n, int min)
    {
        var p = min;
        while ((long)p * p <= n)
        {
            if (n % p == 0) return p;
            ++p;
        }
        return n;
    }
    static List<int> PDiv(int n, int[] minPDivList)
    {
        var p = minPDivList[n];
        if (n == p)
        {
            var dic = new List<int>();
            dic.Add(p);
            return dic;
        }
        else
        {
            var dic = PDiv(n / p, minPDivList);
            dic.Add(p);
            return dic;
        }
    }
}