object Main {
  def main(args: Array[String]) = {
    var min: Double = 1000000 + 1
    var max: Double = -1
    for (x <- io.Source.stdin.getLines()) {
      val y = x.toDouble
      if (y < min) min = y
      else if (y > max) max = y
    }
    println(max - min)
  }
}