# region template
import typing
import sys
import math
import collections
import bisect
import itertools
import heapq
import copy


def ni(): return int(sys.stdin.buffer.readline())
def ns(): return map(int, sys.stdin.buffer.readline().split())
def ns1(): return map(lambda x: int(x)-1, sys.stdin.buffer.readline().split())
def na(): return list(map(int, sys.stdin.buffer.readline().split()))
def na1(): return list(map(lambda x: int(x)-1, sys.stdin.buffer.readline().split()))
def nall(): return list(map(int, sys.stdin.buffer.read().split()))
def flush(): return sys.stdout.flush()
def nic(): return int(sys.stdin.readline())
def nsc(): return map(int, sys.stdin.readline().split())
def nac(): return list(map(int, sys.stdin.readline().split()))
def na1c(): return list(map(lambda x: int(x)-1, sys.stdin.readline().split()))
# endregion


# sys.setrecursionlimit(10**7+1)
inf = 10**20
mod = 10**9+7
# mod = 998244353


def Eratosthenes(n):  # N以下のすべての値の素数判定 O(NloglogN)、N=10^7のとき4*10^7くらい
    a = [True]*(n + 1)
    a[0], a[1] = False, False
    if n >= 2:
        for i in range(2, n + 1):
            if a[i]:
                for j in range(i+i, n + 1, i):
                    a[j] = False
    # a = [i for i in range(n+1) if a[i]]
    return a


def main():
    n = ni()
    a = na()

    lim = max(a)
    kushi = Eratosthenes(lim)
    base = 0
    over = 0
    for ai in a:
        if kushi[ai]:
            base += 1
        elif ai != 1:
            over += 1

    res = 0
    # 0:white win, 1:black win
    b = base % 2
    o = over % 2
    if o:
        if b:
            res = 1
        else:
            res = 0
    else:
        if b:
            res = 1
        else:
            res = 0

    print('white' if res^1 else 'black')


if __name__ == '__main__':
    main()