N = 10 ** 6
prime_list = [] # 素数リスト
lpf = [0] * (N + 1) # 最小素因数
for i in range(2, N + 1):
    if not lpf[i]:
        lpf[i] = i
        prime_list.append(i)
    a = lpf[i]
    for p in prime_list:
        if p > a or p * i > N: break
        lpf[p*i] = p
# print("lpf =", lpf)
L = [0] * (N + 1)
for i in range(2, N + 1):
    p = lpf[i]
    L[i] = L[i//p] + 1
n = int(input())
A = [int(a) for a in input().split()]
s = 0
for a in A:
    s ^= L[a]
print("white" if s else "black")