import scala.io.Source.stdin

object Main {
  def main(args: Array[String]) = {
    var min: Double = 1000000 + 1
    var max: Double = -1
    val input = stdin.getLines.map(_.toDouble)

    for (y <- input) {
      if (y < min) min = y
      else if (y > max) max = y
    }

    println(max - min)
  }
}