object Main {
  def main(args: Array[String]): Unit = {
    val inputs = scala.io.StdIn.readLine.split( " " ).map{ _.toInt }
    var count = 0

    ( inputs( 0 ) to inputs( 1 ) ).foreach{ i =>
      if( i%inputs( 2 ) == 0 ) count += 1
    }
    println( count )
  }
}