import sys

# sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = 10**20
# md = 998244353
md = 10**9+7

class Sieve:
    def __init__(self, n):
        self.plist = [2]  # n以下の素数のリスト
        min_prime_factor = [2, 0]*(n//2+1)
        for x in range(3, n+1, 2):
            if min_prime_factor[x] == 0:
                min_prime_factor[x] = x
                self.plist.append(x)
                if x**2 > n: continue
                for y in range(x**2, n+1, 2*x):
                    if min_prime_factor[y] == 0:
                        min_prime_factor[y] = x
        self.min_prime_factor = min_prime_factor

    def isprime(self, x):
        return self.min_prime_factor[x] == x

    # これが素因数分解(prime factorization)
    def pfct(self, x):
        pp, ee = [], []
        while x > 1:
            mpf = self.min_prime_factor[x]
            if pp and mpf == pp[-1]:
                ee[-1] += 1
            else:
                pp.append(mpf)
                ee.append(1)
            x //= mpf
        return ee

mx = 1000005
n = II()
aa = LI()
sv = Sieve(mx)

win = 0
for a in aa:
    win ^= sum(sv.pfct(a))

print("white" if win else "black")