# 1 ~ Nの整数を全て素因数分解する O(N√N) -> O(NlogN)

class FastFactorization:
    def __init__(self, N):
        self.N = N
        self.is_prime = [True] * (N+1)
        self.min_factor = [-1] * (N+1) # min_factor[i]:整数iを割り切る最小の素数

        self.Eratosthenes()

    # 前処理 O(N loglogN)
    def Eratosthenes(self):
        self.is_prime[0] = False
        self.is_prime[1] = False
        self.min_factor[1] = 1

        for p in range(2, self.N+1):
            if not self.is_prime[p]:
                continue
            self.min_factor[p] = p
            q = p + p
            while q <= N:
                self.is_prime[q] = False
                if self.min_factor[q] == -1:
                    self.min_factor[q] = p
                q += p
            
    # 高速素因数分解
    def factorize(self, n):
        res = []
        while n > 1:
            p = self.min_factor[n]
            power = 0
            while n % p == 0:
                n //= p
                power += 1
            res.append((p, power))
        return len(res) - 1

    def main(self):
        self.Eratosthenes()
        for i in range(2, self.N+1):
            print(len(self.factorize(i)))


N = int(input())
A = list(map(int, input().split()))
ff = FastFactorization(max(A) + 1)
grundy = 0

for a in A:
    grundy ^= ff.factorize(a)

if grundy == 0:
    print('black')
else:
    print('white')