#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    int N; cin >> N;
    vector<int> A(N);
    rep(i,N) cin >> A[i];

    int MAX_A = 1e6;
    vector<int> pf_cnt(MAX_A + 1, 1);
    pf_cnt[1] = 0;
    for(int i = 2; i * i <= MAX_A; i++) if(pf_cnt[i] == 1)
        for(int j = 2; i * j <= MAX_A; j++) pf_cnt[i * j] = pf_cnt[i] + pf_cnt[j];
    
    int XOR = 0;
    rep(i,N) XOR ^= pf_cnt[A[i]];
    cout << (XOR == 0 ? "black" : "white") << endl;
}