#include<bits/stdc++.h>
#include<random>
using namespace std;
#define int long long
#define REP(i,m,n) for(int i=(m);i<(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(c) (c).rbegin(),(c).rend()
#define mp make_pair
#define endl '\n'
//#define vec vector<ll>
//#define mat vector<vector<ll> >
#define fi first
#define se second
#define double long double
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> pll;
//typedef long double ld;
typedef complex<double> Complex;
const ll INF=1e9+7;
const ll MOD=998244353;
const ll inf=INF*INF;
const ll mod=INF;
const ll MAX=1000010;
const double PI=acos(-1.0);
typedef vector<vector<ll> > mat;
typedef vector<ll> vec;


signed main(){
    ll n;cin>>n;
    vector<ll>a(MAX);
    vector<ll>b(n);
    rep(i,n)cin>>b[i];
    vector<vector<ll> >p(MAX);
    REP(i,2,MAX){
        ll j=1;
        sort(all(p[i]));
        rep(l,p[i].size()){
            if(l>0&&p[i][l]==p[i][l-1])continue;
            if(p[i][l]==j)j++;
            else break;
        }
        a[i]=j;
        ll k=1;
        while(k*i<MAX){
            p[k*i].pb(a[i]);
            k++;
        }
    }
    ll ans=0;
    rep(i,n){
        ans^=a[b[i]];
    }
    if(ans!=0){
        cout<<"white"<<endl;
    }else{
        cout<<"black"<<endl;
    }
}