#include <bits/stdc++.h>

using namespace std;

int v[1000005];
void sieve() {
	v[1] = 1;
	for (int i = 2; i <= 1000000; ++i) {
		if (0 != v[i]) continue;
		v[i] = i;
		for (int j = i * 2; j <= 1000000; j += i) {
			if (0 == v[j]) v[j] = i;
		}
	}
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int n; cin >> n;
	sieve();
	
	int nim = 0;
	while (n--) {
		int a; cin >> a;
		int c = 0;
		while (a != 1) {
			a /= v[a];
			c ++;
		}
		nim ^= c;
	}
	cout << (nim ? "white" : "black") << endl;
	return 0;
}