#include <bits/stdc++.h>
//#include<atcoder/all>
using namespace std;
//using namespace atcoder;
using ll = long long;
#define all(A) A.begin(),A.end()
using vll = vector<ll>;
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)
using Graph = vector<vector<ll>>;


int main() {
    vector<bool> P(1e6+10, true);
    P[0] = P[1] = false;
    rep(p, 1e6 + 10) {
        if (P[p]) {
            for (ll j = p + p; j <= 1e6 + 4; j += p) {
                P[j] = false;
            }
        }

    }
    ll N;
    cin >> N;
    ll AN = 0;
    rep(i, N) {
        ll A;
        cin >> A;
        if (!P[A])AN++;
        
    }
    cout << (AN % 2 == 0 ? "black" : "white") << endl;
}