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

const int MAX = 1e6;

int main() {
    int N;
    cin >> N;
    vector<int> A(N);
    for (int i = 0; i < N; i++) cin >> A[i];
    vector<int> spf(MAX+1);
    for (int i = 0; i <= MAX; i++) spf[i] = i;
    for (int i = 2; i*i <= MAX; i++) {
        if (spf[i] == i) {
            for (int j = 2*i; j <= MAX; j += i) {
                if (spf[j] == j) spf[j] = i;
            }
        }
    }

    int n = 0;
    for (int i = 0; i < N; i++) {
        int a = A[i];
        int cnt = 0;
        while (a != 1) {
            a /= spf[a];
            cnt++;
        }
        n ^= cnt;
    }

    if (n) cout << "white" << endl;
    else cout << "black" << endl;
}