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

# 素因数の数
def n_factorization(x):
    cnt = 0
    for p in PL:
        if x in PL:
            cnt += 1
            return cnt
        while x % p == 0:
            cnt += 1
            x //= p
        if x == 1:
            return cnt
    # ここには来ないはず
    print("factorization error")
    return "error"


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_factorization(A[i]))

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