import java.io.{BufferedOutputStream, BufferedReader, InputStreamReader, PrintWriter}

object Main {
  def main(args: Array[String]): Unit = {
    val in = new BufferedReader(new InputStreamReader(System.in))
    val out = new PrintWriter(new BufferedOutputStream(System.out))
    val x = in.readLine().toLong

    var current = 100L
    var years = 0

    while (current < x) {
      current = (current * 1.01).toLong
      years += 1
    }

    out.println(years)
    out.flush()
  }
}
