def seachPrimeNum(N):
    max = int(N**0.5)
    seachList = [i for i in range(2,N+1)]
    primeNum = []
    while seachList[0] <= max:
        primeNum.append(seachList[0])
        tmp = seachList[0]
        seachList = [i for i in seachList if i % tmp != 0]
    primeNum.extend(seachList)
    return primeNum

def adic(dic,x):
    if x in dic:
        dic[x] += 1
    else:
        dic[x] = 1
    return

def factorization(x):
    dic = {}
    for p in PL:
        if x in PL:
            adic(dic,x)
            return dic
        while x % p == 0:
            adic(dic,p)
            x //= p
        if x == 1:
            return dic
    # ここには来ないはず
    print("factorization error")
    return "error"

# 約数の数
def N_divisors(x):
    dic = factorization(x)
    ret = 1
    for v in dic.values():
        ret *= (v+1)
    return ret

N = int(input())
A = list(map(int,input().split()))
PL = set(seachPrimeNum(max(max(A),2)))
G = 0
for i in range(N):
    if A[i] != 1:
        G ^= (N_divisors(A[i]) - 1)

if G == 0:
    print("black")
else:
    print("white")