N = int(input())
A = list(map(int,input().split()))
T = [0]*(10**6+1)
for i in range(2,10**6+1):
    if T[i]==0:
        for j in range(i,10**6+1,i):
            T[j]=i

XOR = []
for a in A:
    c = 0
    while T[a]>0:
        c+=1
        a = a//T[a]
    XOR.append(c)

nim = 0
for xor in XOR:
    nim^=xor
if nim==0:
    print('black')
else:
    print('white')