#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
//const long nPrime = 1000000007;
//const long nPrime = 998244353;
typedef long long ll;
int main() {
    long nMax = 1000001;
    vector<long> viGrundy(nMax,0);
    vector<set<long>> vsiNum(nMax);
    for(long i = 1; i < nMax; i++){
        vsiNum[i].insert(0);
    }
    for(long i = 2; i < nMax; i++){
        for(auto itr = vsiNum[i].begin(); itr != vsiNum[i].end(); itr++){
            if(*itr == viGrundy[i]){
                viGrundy[i]++;
            } else {
                break;
            }
        }
        for(long j = 2; i*j < nMax; j++){
            vsiNum[i*j].insert(viGrundy[i]);
        }
    }
    
    long n;
    cin >> n;
    long nSum = 0;
    for(long i = 0; i < n; i++){
        long a;
        cin >> a;
        nSum ^= viGrundy[a];
    }
    if(nSum != 0){
        cout << "white" << endl;
    } else {
        cout << "black" << endl;
    }
    
    return 0;
}