import math

N = 2*10**6
spf = [-1]*(N+1)
for i in range(N+1):
    spf[i] = i
for i in range(2, int(math.sqrt(N))+1):
    if spf[i] == i:
        for j in range(i*2, N+1, i):
            if spf[j] == j:
                spf[j] = i

def factorize(n):
    d = {}
    while n != 1:
        p = spf[n]
        if p in d:
            d[p] += 1
        else:
            d[p] = 1
        n //= p
    return d

n = int(input())
A = list(map(int, input().split()))
t = 0
for a in A:
    d = factorize(a)
    c = 0
    for k, v in d.items():
        c += v
    t ^= c
if t == 0:
    print('black')
else:
    print('white')