#include <bits/stdc++.h>
//eolibraries
#define lnf 3999999999999999999
#define inf 999999999
#define fi first
#define se second
#define pb push_back
#define ll long long
#define ld long double
#define all(c) (c).begin(),(c).end()
#define sz(c) (ll)(c).size()
#define make_unique(a) sort(all(a)),a.erase(unique(all(a)),a.end());
#define rep(i,n) for(ll i=0;i<n;i++)
#define drep(i,n) for(ll i=n-1;i>=0;i--)
#define crep(i,x,n) for(ll i=x;i<n;i++)
#define vec(...) vector<__VA_ARGS__>
#define _3sSOzgI ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
//eodefine
using namespace std;
using pii=pair<ll,ll>;
using vi=vec(ll);
const ll mxn=3000002;

int main(){
_3sSOzgI;
	vi cnt(mxn+10,0);
	for(int i=2;i<=mxn;i++){
		if(cnt[i]==0) cnt[i]=1;
		for(int j=i;j<=mxn;j+=i){
			if(cnt[j]<cnt[i]+1) cnt[j]=cnt[i]+1;
		}
	}
	ll n;
	cin>>n;
	ll xr=0;
	rep(i,n){
		ll x;
		cin>>x;
		xr^=cnt[x];
	}
	if(xr==0){
		cout<<"black\n";
	}else{
		cout<<"white\n";
	}
//	
	return 0;
}