#include <iostream>
using namespace std;

int A[100009];
int x = 0;
int N;

int factorize(int x){
    for (int i = 2; i * i <= x; i++){
        int cnt = 0;
        if (x % i == 0){
            while (x % i == 0) x = x/ i;
        }
    }
    return 0;
}

int main(){
    cin >> N;
    for (int i = 0; i < N; i++){
        cin >> A[i];
    }
    for (int i = 0; i < N; i++){
        int cnt;
        cnt = factorize(A[i]);
        x ^= cnt;
    }
    if (x == 0){
        cout << "black" << endl;
    }
    else{
        cout << "white" << endl;
    }
    return 0;
}