mod = 1000000007
eps = 10**-9


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

    M = 10 ** 6
    min_factor = list(range(M+1))
    for i in range(2, M+1):
        for x in range(1, M+1):
            if i * x > M:
                break
            if min_factor[i*x] == i*x:
                min_factor[i*x] = i

    G = [0] * (M+1)
    for i in range(2, M+1):
        P = {}
        ii = i
        while ii != 1:
            p = min_factor[ii]
            if p not in P:
                P[p] = 0
            P[p] += 1
            ii //= p
        for p in P:
            G[i] += P[p]
    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()