def prime_count(K):
    res=0
    p=2
    while(p*p<=K):
        while(K%p==0):
            res+=1
            K//=p
        p+=1
    if K>1:
        res+=1
    return res
N=int(input())
A=[int(i) for i in input().split()]
X=[prime_count(a) for a in A]
Grundy=0
for i in range(N):
    Grundy^=X[i]
if Grundy==0:
    print("black")
else:
    print("white")