import sys

def main():
    max_num = 10**6
    min_prime = [0] * (max_num + 1)
    primes = []
    for i in range(2, max_num + 1):
        if min_prime[i] == 0:
            min_prime[i] = i
            primes.append(i)
        for p in primes:
            if p > min_prime[i] or i * p > max_num:
                break
            min_prime[i * p] = p

    data = list(map(int, sys.stdin.read().split()))
    n = data[0]
    a = data[1:n+1]

    xor_sum = 0
    for x in a:
        if x == 1:
            xor_sum ^= 0
            continue
        s = 0
        tmp = x
        while tmp > 1:
            p = min_prime[tmp]
            cnt = 0
            while tmp % p == 0:
                tmp = tmp // p
                cnt += 1
            s += cnt
        xor_sum ^= s

    if xor_sum != 0:
        print("white")
    else:
        print("black")

if __name__ == "__main__":
    main()