N = int(input())
A = list(map(int, input().split()))

def fac(M):
    if M == 1:
        return 0
    else:
        cnt = 0
        s = 2
        while s*s<=M:
            if M%s==0:
                while M%s==0:
                    M//=s
                    cnt += 1
            s += 1
        if M>1:
            cnt += 1
        return cnt

cal = [-1]*(10**6+1)
res = 0
for i in range(N):
    if cal[A[i]] == -1:
        cal[A[i]] = fac(A[i])
    res ^= cal[A[i]]
if res==0:
    print('black')
else:
    print('white')