object Main {
  def main(args: Array[String]) {
    val Array(x, y, z) = args map {_.toInt}
    println(tarai_(x, y, z))
    // これは遅い
    // println(tarai(x, y, z))
  }

  def tarai_(x: => Int, y: => Int, z: => Int): Int =
    if (x <= y)
      y
    else
      tarai_(
        tarai_(x - 1, y, z),
        tarai_(y - 1, z, x),
        tarai_(z - 1, x, y)
      )

  def tarai(x: Int, y: Int, z: Int): Int =
    if (x <= y)
      y
    else
      tarai(
        tarai(x - 1, y, z),
        tarai(y - 1, z, x),
        tarai(z - 1, x, y)
      )
}