object Main extends App{
    val sc = new java.util.Scanner(System.in)
    val w, d = sc.nextInt
    def work(w: Int, d: Int): Unit = d match{
        case 1 => println(w)
        case _ => work(w - (w / d / d).toInt, d - 1)    // d * d : intの範囲を超える
    }
    work(w, d)   
}