import sys

def main():
    input = sys.stdin.read().split()
    N = int(input[0])
    A = list(map(int, input[1:N+1]))
    
    if N == 0:
        print("black")
        return
    
    max_a = max(A)
    max_spf = 10**6
    
    # Initialize smallest prime factors (spf)
    spf = list(range(max_spf + 1))
    for i in range(2, int(max_spf**0.5) + 1):
        if spf[i] == i:
            for j in range(i * i, max_spf + 1, i):
                if spf[j] == j:
                    spf[j] = i
    
    grundy_xor = 0
    
    for a in A:
        if a == 1:
            grundy_xor ^= 0
            continue
        x = a
        total = 0
        while x != 1:
            p = spf[x]
            count = 0
            while x % p == 0:
                count += 1
                x = x // p
            total += count
        grundy_xor ^= total
    
    print("white" if grundy_xor != 0 else "black")

if __name__ == "__main__":
    main()