def primeset(N): #N以下の素数をsetで求める.エラトステネスの篩O(√Nlog(N))
    lsx = [1]*(N+1)
    for i in range(2,int(-(-N**0.5//1))+1):
        if lsx[i] == 1:
            for j in range(i,N//i+1):
                lsx[j*i] = 0
    setprime = set()
    for i in range(2,N+1):
        if lsx[i] == 1:
            setprime.add(i)
    return setprime

def factorization_all_c(n):#n以下の自然数すべてをを素因数分解,素因数の数をカウント
    lspn = [0 for i in range(n+1)]
    lsnum = [i for i in range(n+1)]
    lsp = list(primeset(n))
    lsp.sort()
    for p in lsp:
        for j in range(1,n//p+1):
            cnt = 0
            while lsnum[p*j]%p==0:
                lsnum[p*j] //= p
                cnt += 1
            lspn[j*p]+=cnt
    return lspn

N = int(input())
lsA = list(map(int,input().split()))

fa = factorization_all_c(max(lsA))
ans = 0
for i in range(N):
    ans ^= fa[lsA[i]]
if ans:
    print('white')
else:
    print('black')