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()

def factorization(n):
    arr = []
    temp = n
    for i in range(2, int(-(-n**0.5//1))+1):
        if temp%i==0:
            cnt=0
            while temp%i==0:
                cnt+=1
                temp //= i
            arr.append([i, cnt])

    if temp!=1:
        arr.append([temp, 1])

    if arr==[]:
        arr.append([n, 1])

    return arr

Nim = []
for get in A:
    now = factorization(get)
    x = 0
    for _, cnt in now:
        x += cnt
    Nim.append(x)

x = 0
for get in Nim:
    x ^= get

if not x:
    print("black")
else:
    print("white")