mod = 1000000007
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline

    M = 10 ** 6
    div = [[] for _ in range(M+1)]
    for i in range(1, M+1):
        for x in range(2, M+1):
            if i * x > M:
                break
            div[i*x].append(i)

    G = [0] * (M+1)
    for i in range(2, M+1):
        S = set()
        for d in div[i]:
            S.add(G[i // d])
        for j in range(M+1):
            if j not in S:
                G[i] = j
                break
    N = int(input())
    A = list(map(int, input().split()))
    g = 0
    for a in A:
        g ^= G[a]
    if g:
        print("white")
    else:
        print("black")


if __name__ == '__main__':
    main()