def factor(N):
    factor = set()

    i = 1
    while i*i <= N:
        if N % i == 0:
            factor.add(i)
            factor.add(N // i)
        i += 1
    return len(factor) - 1


N = int(input())
A = list(map(int, input().split()))

grundy = 0

for a in A:
    grundy ^= factor(a)

if grundy == 0:
    print('black')
else:
    print('white')