#!/usr/bin/env python3
import sys

def main():
    N = int(input())
    A = list(map(int, input().split()))
    dp = [-1] * N   # 0 : white, 1 : black
    dp[0] = 0
    def primeFactrization(n: int) -> list:
        primeFactors = list()
        i = 2
        while i * i <= n:
            while n % i == 0:
                primeFactors.append(i)
                n //= i
            i += 1
        if n != 1:
            primeFactors.append(n)
        return primeFactors
    pf = [len(primeFactrization(aa)) for aa in A]
    for i in range(N - 1):
        if pf[i + 1] % 2 == 0:
            dp[i + 1] = dp[i]
        else:
            dp[i + 1] = dp[i] ^ 1
    print("white" if dp[-1] == 0 else "black")
    return

if __name__ == '__main__':
    main()