import sys
from operator import itemgetter
from collections import defaultdict, deque
import heapq
import bisect
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)

Max = 10 ** 6 + 10
N = ip()
A = lp()

spf = [0 for _ in range(Max)]

for i in range(2, Max):
    if spf[i] != 0:
        continue
    for j in range(i, Max, i):
        spf[j] = i

Xor = 0
for get in A:
    res = 0
    while get != 1:
        now = spf[get]
        res += 1
        get //= now
    Xor ^= res

if Xor:
    print("white")
else:
    print("black")