import java.util.Scanner

object Main extends App {
  val sc = new Scanner(System.in)

  val x = sc.nextLong()
  val year = Iterator.iterate((0, 100L)) { case (year, yen) => (year + 1, (yen * 1.01).toLong) }
      .find(x <= _._2).get._1
  println(year)
}
