#!/usr/bin/env python3
import sys
import functools

def main():
    N = int(input())
    A = list(map(int, input().split()))
    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]
    ans = 0
    for i in pf:
        ans ^= i
    print("white" if ans else "black")
    return

if __name__ == '__main__':
    main()