#include <bits/stdc++.h>

using namespace std;
void fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

int main() {
    fast_io();
    const int M = 1e6;
    vector<vector<int>> fac(M + 1);
    for (int i = 1; i <= M; i++) {
        fac[i].push_back(i);
    }
    for (int i = 2; i <= M; i++) {
        for (int j = 2 * i; j <= M; j += i) {
            fac[j].push_back(i);
        }
    }
    vector<int> cnt(M + 1);
    cnt[1] = 0;
    for (int i = 2; i <= M; i++) {
        if (fac[i].size() == 1) {
            cnt[i] = 1;
        } else {
            cnt[i] = cnt[i / fac[i][1]] + 1;
        }
    }
    int n;
    cin >> n;
    int grundy = 0;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
        grundy ^= cnt[a[i]];
    }
    cout << (grundy ? "white" : "black") << endl;
}