m = 1001001
pl = []
lpf = [0] * m
for i in range(2, m):
    if not lpf[i]:
        lpf[i] = i
        pl.append(i)
    a = lpf[i]
    for p in pl:
        if p > a or p * i >= m: break
        lpf[p*i] = p
L = [0] * m
for i in range(2, m): L[i] = L[i//lpf[i]] + 1
input()
s = 0
for a in input().split(): s ^= L[int(a)]
print("white" if s else "black")