import java.util.*

fun main(args: Array<String>) {
  val sc = Scanner(System.`in`)
  val x = sc.nextLong()

  println(abc165b(x))
}

private fun abc165b(x: Long): Long {
  var bank = 100L
  var ans = 0L
  while (bank < x) {
    bank = bank + bank / 100
    ans++
  }
  return ans
}
