from math import sqrt, ceil def Sieve(n): lst = [True] * (n + 1) S = set() for i in range(2, ceil(sqrt(n)) + 1): if lst[i]: for j in range(2 * i, n + 1, i): lst[j] = False for i in range(2, n + 1): if lst[i]: S.add(i) return S N = int(input()) A = list(map(int, input().split())) M = max(A) D = [0] * (M + 1) for p in Sieve(M): now = p while now <= M: for i in range(now, M + 1, now): D[i] += 1 now *= p ans = 0 for a in A: ans ^= D[a] print("white") if ans else print("black")