object Main {
  val sc = new java.util.Scanner(System.in)
  def readLine(): String = sc.nextLine
  def readInts(): Array[Int] = sc.nextLine.split(' ').map(_.toInt)
  def readInt(): Int = sc.nextLine.toInt

  def main(args: Array[String]) {
    val n = readInt
    println(n-1)
  }
}