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

spl = [0 for _ in range(10**6 + 1)]
spl[1] = 1
for i in range(2, 10**6 + 1):
    if spl[i]:
        continue
    for j in range(i, 10**6 + 1, i):
        spl[j] = i

P = [0 for _ in range(n)]
for i in range(n):
    while A[i] > 1:
        A[i] //= spl[A[i]]
        P[i] += 1

state = 0
for i in range(n):
    state ^= P[i]

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