#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
//using mint = modint1000000007;
using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using tlll = tuple<ll, ll, ll>;
constexpr ll INF = 1LL << 60;
template<class T> bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}
template<class T> bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}
ll safemod(ll A, ll M) {return (A % M + M) % M;}
ll divfloor(ll A, ll B) {if (B < 0) {return divfloor(-A, -B);} return (A - safemod(A, B)) / B;}
ll divceil(ll A, ll B) {if (B < 0) {return divceil(-A, -B);} return divfloor(A + B - 1, B);}
#define FINALANS(A) do {cout << (A) << '\n'; exit(0);} while (false)

int main()
{
  ll N;
  cin >> N;
  vector<ll> A(N);
  for (ll i = 0; i < N; i++)
  {
    cin >> A.at(i);
  }

  const ll M = 1333333;
  vector<ll> primecount(M, 0);
  for (ll p = 2; p < M; p++)
  {
    if (primecount.at(p) == 0)
    {
      for (ll k = 1; k * p < M; k++)
      {
        ll tmp = k * p;
        while (tmp % p == 0)
        {
          tmp /= p;
          primecount.at(k * p)++;
        }
      }
    }
  }

  vector<ll> B(N);
  for (ll i = 0; i < N; i++)
  {
    B.at(i) = primecount.at(A.at(i));
    //cerr << B.at(i) << endl;
  }

  ll x = 0;
  for (ll i = 0; i < N; i++)
  {
    x ^= B.at(i);
  }

  cout << (x == 0 ? "black\n" : "white\n");
}