def sieve(n):
    is_prime = [True for _ in range(n+1)]
    is_prime[0] = False

    for i in range(2, n+1):
        if is_prime[i-1]:
            j = i * i
            while j <= n:
                is_prime[j-1] = False
                j += i
    table = [ i for i in range(1, n+1) if is_prime[i-1]]
    return [False]+is_prime, table



N = int(input())
A = list(map(int, input().split())) 
T,_ =  sieve(10**6+1)
p = 0
np = 0
for a in A:
    if a>1: 
        if T[a]:
            p+=1
        else:
            np+=1
if (p+np)%2==1 or np==1:
    print('white')
else:
    print('black')