#include <bits/stdc++.h>
using namespace std;

struct primenumber {
    vector<int> spf;
    primenumber(int N) {
        init(N);
    }
    void init(int N) {
        spf.assign(N+1,0);
        for(int i = 0; i <= N; i++) {
            spf[i] = i;
        }
        for(int i = 2; i*i <= N; i++) {
            if(spf[i] == i) {
                for(int j = i*i; j <= N; j += i) {
                    if(spf[j] == j) {
                        spf[j] = i;
                    }
                }
            }
        }
    }
    int get(int n) {
        int m = 0;
        while(n != 1) {
            m++;
            n /= spf[n];
        }
        return m;
    }
};

int main() {
    int N;
    cin >> N;
    primenumber zz(1000001);
    int a = 0;
    for(int i = 0; i < N; i++) {
        int A;
        cin >> A;
        a ^= zz.get(A);
    }
    cout << ((a == 0)?"black":"white") << endl;
}