import sys
from operator import itemgetter
stdin=sys.stdin
sys.setrecursionlimit(10 ** 8)

ip=lambda: int(sp())
fp=lambda: float(sp())
lp=lambda:list(map(int,stdin.readline().split()))
sp=lambda:stdin.readline().rstrip()
Yp=lambda:print('Yes')
Np=lambda:print('No')
inf = 1 << 60
eps = 1e-9
sortkey = itemgetter(0)

def primes(n):
    is_prime = [True] * (n + 1)
    is_prime[0] = False
    is_prime[1] = False
    for i in range(2, int(n**0.5) + 1):
        if not is_prime[i]:
            continue
        for j in range(i * 2, n + 1, i):
            is_prime[j] = False
    return [i for i in range(n + 1) if is_prime[i]]

N = ip()
A = lp()

B = [0 for _ in range(10 ** 6 + 1)]
prime = primes(10 ** 6)
for get in prime:
    now = get
    while now < 10 ** 6:
        temp = now
        while temp <= 10 ** 6:
            B[temp] += 1
            temp += now
        now *= get

x = 0
for get in A:
  x ^= B[get]

if not x:
    print("black")
else:
    print("white")