import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
sys.setrecursionlimit(10**7)
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
MAX = 10**6
arr = [-1] * (MAX + 1)
for i in range(2, int(MAX**0.5)+1):
    j = 1
    while i * j < len(arr):
        if arr[i * j] < 0:
            arr[i * j] = i
        j += 1
for i in range(1, len(arr)):
    if arr[i] == -1:
        arr[i] = i

def fastfactorization(n):
    res = 0
    while n>1:
        res+=1
        n//=arr[n]
    return res

n = ni()
a = na()

z = 0
for i in range(n):
    c = fastfactorization(a[i])
    z^=c

if z==0:
    print("black")
else:
    print("white")