object Dtb {
  def main(args: Array[String]) {
    val t1 = java.lang.System.nanoTime()

    println(N(10,'ind))
    val t2 = java.lang.System.nanoTime()
    println("depth 10 elapsed time: " + ((t2-t1)/1000000) + " msec")

    println(N(100,'ind))
    val t3 = java.lang.System.nanoTime()
    println("depth 100 elapsed time: " + ((t3-t2)/1000000) + " msec")

    println(N(1000,'ind))
    val t4 = java.lang.System.nanoTime()
    println("depth 1000 elapsed time: " + ((t4-t3)/1000000) + " msec")

    println(N(10000,'ind))
    val t5 = java.lang.System.nanoTime()
    println("depth 10000 elapsed time: " + ((t5-t4)/1000000) + " msec")

    println(N(10000000,'ind))
    val t6 = java.lang.System.nanoTime()
    println("depth 10000000 elapsed time: " + ((t6-t5)/1000000) + " msec")
  }

  def N(n: Int,X: Any): Any =
    if (n == 0) 'ind else N(n-1,X)

  def I(n: Int,X: Any): Any =
    if (n == 0) 'ind else N(n-1,X)

  def J(n: Int,X: Any): Any =
    if (n == 0) 'ind else N(n-1,X)
}