object Main extends App {
	val N = scala.io.StdIn.readInt
	
	val a = new Array[Int](N-1)
	val b = new Array[Int](N-1)

	for(i<-0 until N-1){
		val temp = scala.io.StdIn.readLine.split(" ").map(_.toInt)
		a(i) = temp(0)
		b(i) = temp(1)
	}

	val c = new Array[Boolean](N-1)

	for(i<-0 until N-1){
		if(a(i) == 1) c(b(i) - 1) = true
	}

	var re = false

	for(i<-0 until N-1){
		if(c(i)) re = !re
	}

	if(re)println("Alice")
	else println("Bob")
}