n=int(input())
A=[int(i) for i in input().split()]
ans=0
sosu=[]
fu=[0 for i in range(1001)]
for i in range(2,1001):
    if fu[i]==0:
        sosu.append(i)
        for q in range(i,1001,i):
            fu[q]=1

for num in A:
    sub=0
    for i in sosu:
        while num%i==0:
            num//=i
            sub+=1
    ans^=sub
print("white") if ans else print("black")