n=int(input())
a=list(map(int,input().split()))
x=[]
###########
prime_num=max(a)+10
###########


min_prime=[-1]*(prime_num+1) #2以上の自然数に対して最小の素因数を表す
min_prime[0]=0
min_prime[1]=1
i=2
prime=[]
while i<=prime_num:
    if min_prime[i]==-1:
        min_prime[i]=i
        prime.append(i)
    for j in prime:
        if i*j>prime_num or j>min_prime[i]:break
        min_prime[j*i]=j
    i+=1

def prifac(n):
    res={}
    x=n
    while x>1:
        p=min_prime[x]
        if p in res:res[p]+=1
        else:res[p]=1
        x//=p
    return res
for i in range(n):
    res=0
    p=prifac(a[i])
    for key in p:res+=p[key]
    x.append(res)

ans=0
for i in range(n):
    ans^=x[i]
print("white" if ans>0 else "black")