class osa_k:
    min_factor = []
    def __init__(self, n):
        self.min_factor = list(range(n + 1))
        i = 2
        while i * i <= n:
            if self.min_factor[i] < i:
                i += 1
                continue
            for j in range(i*i, n + 1, i):
                if self.min_factor[j] == j:
                    self.min_factor[j] = i
            i += 1

    def factor(self, n):
        res = []
        while n > 1:
            res.append(self.min_factor[n])
            n //= self.min_factor[n]
        return len(res)

    def divisors(self, n):
        res = [1]
        while n > 1:
            x = self.min_factor[n]
            cnt = 0
            while n % x == 0:
                cnt += 1
                n //= x
            t = []
            p = 1
            for i in range(cnt + 1):
                for j in range(len(res)):
                    t.append(res[j] * p)
                p *= x
            res = t[:]
        return res


n = int(input())
a = list(map(int, input().split()))
os = osa_k(1000000)
g = 0
for x in a:
    g ^= os.factor(x)
if g == 0:
    print('black')
else:
    print('white')