U = 10 ** 6


def prime_sieve(N):
    #sieve[i] : iの最小の素因数
    sieve = [0] * (N + 1)
    prime = []
    for i in range(2, N + 1):
        if sieve[i] == 0:
            sieve[i] = i
            prime.append(i)
        for p in prime:
            if p > sieve[i] or i * p > N:
                break
            sieve[i * p] = p
    return sieve


sieve = prime_sieve(U + 5)
N = int(input())
A = list(map(int, input().split()))

xor = 0
for a in A:
    cnt = 0
    while sieve[a] != 0:
        cnt += 1
        a //= sieve[a]
    xor ^= cnt

if xor:
    print("white")
else:
    print("black")