n = int(input())
alst = list(map(int, input().split()))
x = 0

for a in alst:
    cnt = 0
    j = 2
    while j * j <= a:
        while a % j == 0:
            a //= j
            cnt += 1
        j += 1
    if a != 1:
        cnt += 1
    x ^= cnt
    
if x == 0:
    print("black")
else:
    print("white")