#include <bits/stdc++.h>
using namespace std;
int main(){
  int N;
  cin >> N;
  vector<int> A(N);
  for (int i = 0; i < N; i++){
    cin >> A[i];
  }
  vector<vector<int>> f(1000001);
  for (int i = 1; i <= 1000000; i++){
    for (int j = i * 2; j <= 1000000; j += i){
      f[j].push_back(i);
    }
  }
  vector<int> grundy(1000001, 0);
  for (int i = 2; i <= 1000000; i++){
    set<int> st;
    for (int j : f[i]){
      st.insert(grundy[j]);
    }
    while (st.count(grundy[i]) == 1){
      grundy[i]++;
    }
  }
  int X = 0;
  for (int i = 0; i < N; i++){
    X ^= grundy[A[i]];
  }
  if (X > 0){
    cout << "white" << endl;
  } else {
    cout << "black" << endl;
  }
}