#include using namespace std; #define rep(i, n) for (int i = 0; i < n; i++) #define rep2(i, x, n) for (int i = x; i <= n; i++) #define rep3(i, x, n) for (int i = x; i >= n; i--) #define each(e, v) for (auto &e : v) #define pb push_back #define eb emplace_back #define all(x) x.begin(), x.end() #define rall(x) x.rbegin(), x.rend() #define sz(x) (int)x.size() using ll = long long; using pii = pair; using pil = pair; using pli = pair; using pll = pair; const int MOD = 1000000007; // const int MOD = 998244353; const int inf = (1 << 30) - 1; const ll INF = (1LL << 60) - 1; template bool chmax(T &x, const T &y) { return (x < y) ? (x = y, true) : false; }; template bool chmin(T &x, const T &y) { return (x > y) ? (x = y, true) : false; }; struct io_setup { io_setup() { ios_base::sync_with_stdio(false); cin.tie(NULL); cout << fixed << setprecision(15); } } io_setup; template vector divisors(const T &n) { vector ret; for (T i = 1; i * i <= n; i++) { if (n % i == 0) { ret.push_back(i); if (i * i != n) ret.push_back(n / i); } } sort(begin(ret), end(ret)); return ret; } template vector> prime_factor(T n) { vector> ret; for (T i = 2; i * i <= n; i++) { int cnt = 0; while (n % i == 0) cnt++, n /= i; if (cnt > 0) ret.emplace_back(i, cnt); } if (n > 1) ret.emplace_back(n, 1); return ret; } template bool is_prime(const T &n) { if (n == 1) return false; for (T i = 2; i * i <= n; i++) { if (n % i == 0) return false; } return true; } // 1,2,...,nのうちkと互いに素である自然数の個数 template T coprime(T n, T k) { vector> ps = prime_factor(k); int m = ps.size(); T ret = 0; for (int i = 0; i < (1 << m); i++) { T prd = 1; for (int j = 0; j < m; j++) { if ((i >> j) & 1) prd *= ps[j].first; } ret += (__builtin_parity(i) ? -1 : 1) * (n / prd); } return ret; } vector Eratosthenes(const int &n) { vector ret(n + 1, true); if (n >= 0) ret[0] = false; if (n >= 1) ret[1] = false; for (int i = 2; i * i <= n; i++) { if (!ret[i]) continue; for (int j = i + i; j <= n; j += i) ret[j] = false; } return ret; } vector Eratosthenes2(const int &n) { vector ret(n + 1); iota(begin(ret), end(ret), 0); if (n >= 0) ret[0] = -1; if (n >= 1) ret[1] = -1; for (int i = 2; i * i <= n; i++) { if (ret[i] < i) continue; for (int j = i + i; j <= n; j += i) ret[j] = min(ret[j], i); } return ret; } int main() { int N; cin >> N; int MAX = 1000000; vector p = Eratosthenes2(MAX); int ans = 0; rep(i, N) { int x; cin >> x; int cnt = 0; while (x > 1) { cnt++; x /= p[x]; } ans ^= cnt; } cout << (ans > 0 ? "white\n" : "black\n"); }