#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef int64_t lint;
#define rep(i, n) for(int i=0; i<n; i++)
#define repx(i, l, n) for(int i=l; i<n; i++)
#define all(v) v.begin(), v.end()
#define show(x) cout << #x << ": " << x << endl;
#define list(x) cout << #x << ": " << x << "  ";
#define pb push_back
using vi = vector<lint>;
using vvi = vector<vector<lint>>;
template<class T> inline void vin(vector<T>& v) { rep(i, v.size()) cin >> v.at(i); }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<class T> inline void drop(T x) { cout << x << endl; exit(0); }
template<class T> void vout(vector<T> v) { rep(i, v.size()) { cout << v.at(i) << ' '; } cout << endl; }
constexpr lint LINF = LLONG_MAX/2;
vector<lint> factorList(lint n) {
	vector<lint> V;
	if (!(n % 2)) {
		while (!(n % 2)) {
			V.push_back(2);
			n /= 2;
		}
	}
	int rn = sqrt(n);
	vector<bool> v(rn+1);
	for(lint i = 3; i <= rn && n > 1; i += 2) {
		if(!v.at(i)) {
			if (!(n % i)) {
				while (!(n % i)) {
					V.push_back(i);
					n /= i;
				}
			}
			v.at(i) = 1;
			for(lint j = i*i; j <= rn; j += i) {
				v.at(j) = 1;
			}
		}
	}
	if (n != 1) V.push_back(n);
	return V;
}

int main() {
	lint N;
	cin >> N;
	vi v(N), w(N);
	vin(v);

	lint a=0, b=0, c=0, x, y, z;
	rep(i, N) {
		if (v[i] == 1) continue;
		w[i] = factorList(v[i]).size();
	}
	rep(i, N) {
		a ^= w[i];
	}
	rep(i, N) {
		if (w[i] == a) drop("white");
	}
	std::cout << "black" << '\n';
}