import math._

object Main {
  def main(args: Array[String]) {
    val sc = new java.util.Scanner(System.in)
    val d = sc.nextLong

    // val s = (d * 108).toString
    // val t = s.substring(0, s.length-2) + "." + s.substring(s.length-2)
    // println(t)

    val x = d * 108
    printf("%d.%02d\n", x/100, x%100)
  }
}