#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;
vector<vector<ll>> fac(1e6+1);
vector<ll> ans(1e6+1, -1);

ll f(ll N){
    if (N == 1) return 0;
    if (ans[N] != -1) return ans[N];
    vector<ll> ok(500);
    for (auto x : fac[N]) ok[f(x)] = 1;
    ll g = 0;
    while(ok[g]) g++;
    return ans[N] = g;
}

int main(){

    ll N, g=0, A;
    cin >> N;
    for (int i=1; i<=1e6; i++){
        for (int j=i*2; j<=1e6; j+=i) fac[j].push_back(i);
    }
    for (int i=0; i<N; i++){
        cin >> A;
        g ^= f(A);
    }
    
    cout << (g == 0 ? "black" : "white") << endl;

    return 0;
}