import sys
from operator import itemgetter
stdin=sys.stdin
sys.setrecursionlimit(10 ** 8)

ip=lambda: int(sp())
fp=lambda: float(sp())
lp=lambda:list(map(int,stdin.readline().split()))
sp=lambda:stdin.readline().rstrip()
Yp=lambda:print('Yes')
Np=lambda:print('No')
inf = 1 << 60
eps = 1e-9
sortkey = itemgetter(0)

N = ip()
A = lp()

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

Nim = 0
for i in range(N):
    res = 0
    while A[i] != 1:
        A[i] = A[i] // spf[A[i]]
        res += 1
    Nim ^= res

ans = "white" if Nim else "black"
print(ans)