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 PDiv(int n, int[] minPDivList) { var p = minPDivList[n]; if (n == p) { var dic = new List(); dic.Add(p); return dic; } else { var dic = PDiv(n / p, minPDivList); dic.Add(p); return dic; } } }