import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		String[] sa = br.readLine().split(" ");
		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = Integer.parseInt(sa[i]);
		}
		br.close();

		int m = 1000001;
		List<List<Integer>> list = new ArrayList<>(m);
		for (int i = 0; i < m; i++) {
			list.add(new ArrayList<>());
		}
		for (int i = 1; i < m; i++) {
			for (int j = i * 2; j < m; j += i) {
				list.get(j).add(i);
			}
		}

		int[] g = new int[m];
		for (int i = 2; i < m; i++) {
			Set<Integer> set = new HashSet<>();
			for (int e : list.get(i)) {
				set.add(g[e]);
			}
			for (int j = 0; ; j++) {
				if (!set.contains(j)) {
					g[i] = j;
					break;
				}
			}
		}

		int x = 0;
		for (int i = 0; i < n; i++) {
			x ^= g[a[i]];
		}
		if (x == 0) {
			System.out.println("black");
		} else {
			System.out.println("white");
		}
	}
}