import java.io.PrintWriter

fun main() {
    val pw = PrintWriter(System.out)

    val x = readInputLine().toLong()

    var current = 100L
    var year = 0L

    while (current < x) {
        current += current / 100
        year++
    }

    pw.println(year)

    pw.flush()
}

fun readInputLine(): String {
    return readLine()!!
}
