object Main {
  def main(args: Array[String]): Unit = {
    import scala.io.StdIn.readLine
    val Array(datX) = readLine.split(" ").map(_.toLong)
    //println(datX)

    var year = 0L
    var money = 100L
    while (money < datX) {
      money += money / 100
      year += 1
      //println(year + " " + money)
    }

    println(year)
  }
}
