import java.io.PrintWriter
import java.util.*
import kotlin.math.*

fun PrintWriter.solve() {
    val n = nextInt()
    val a = Array(n) { nextInt() }
    val size = 1000005
    val isprime = BooleanArray(size) { true }
    val primefac = IntArray(size) { 1 }
    for (p in 2 until size) {
        if (!isprime[p]) continue
        primefac[p] = p
        var i = 1
        while (p * i < size) {
            isprime[p * i] = false
            primefac[p * i] = p
            i++
        }
    }
    val b = IntArray(n) { 0 }
    for (i in 0 until n) {
        var v = a[i]
        while (v > 1) {
            v /= primefac[v]
            b[i]++
        }
    }
    val xor = b.fold(0, Int::xor)
    println(if (xor != 0) "white" else "black")
}

fun main() {
    Thread(null, {
        val writer = PrintWriter(System.out, false)
        writer.solve()
        writer.flush()
    }, "solve", 1.shl(26))
        .apply { setUncaughtExceptionHandler { _, e -> e.printStackTrace(); kotlin.system.exitProcess(1) } }
        .apply { start() }.join()
}

// region Scanner
private var st = StringTokenizer("")
private val br = System.`in`.bufferedReader()

fun next(): String {
    while (!st.hasMoreTokens()) st = StringTokenizer(br.readLine())
    return st.nextToken()
}

fun nextInt() = next().toInt()
fun nextLong() = next().toLong()
fun nextLine() = br.readLine()
fun nextDouble() = next().toDouble()
// endregion