#include <bits/stdc++.h>
using namespace std;

const int M = 30;
const int S = 1000000;
array<bitset<M>, S + 10> mex_vec;
array<int, S + 10> grundy;
int n, fold, a;
int main() {
	for(int i = 2; i <= S; i++) {
		for(int j = 1; j < M; j++) {
			if(mex_vec[i][j] == 0) {
				grundy[i] = j;
				break;
			}
		}
		for(int j = i; j <= S; j += i)
			mex_vec[j][grundy[i]] = 1;
	}

	cin >> n;
	while(n--) {
		cin >> a;
		fold ^= grundy[a];
	}

	cout << (fold ? "white" : "black") << '\n';

	return 0;
}