//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#include <iostream>
#include <algorithm>
using namespace std;
using ll = long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<int>;  using vvi = vector<vi>;
using vl = vector<ll>;   using vvl = vector<vl>;
using vb = vector<bool>; using vvb = vector<vb>;
using vpi = vector<pii>; using vvpi = vector<vpi>;
using vpl = vector<pll>; using vvpl = vector<vpl>;
const int inf = 1 << 30;
const ll INF = 1LL << 60;
#define rep(i,m,n) for (int i = m; i < (int)(n); i++)
#define rrep(i,m,n) for (int i = m; i > (int)(n); i--)

int main(){
    int M = 1000001;
    int n; cin >> n;
    vi P(M,0);
    P[1] = 1;
    for (int i = 2;i < M;i++){
        for (int j = i;j < M; j += i){
            if (P[j] == 0) P[j] = i;
        }
    }
    int judge = 0;
    rep(i,0,n){
        int a,x = 0; cin >> a;
        while (a > 1){
            a /= P[a];
            ++x;
        }
        judge ^= x;
    }
    if (judge != 0) cout << "white" << endl;
    else cout << "black" << endl;
}