import kotlin.math.floor

fun main(){
    val x = readLine()!!.split(" ").map { it.toLong() }[0]
    var a = 100.toDouble()
    for (i in 0 until 1000000000000){
        a *= 1.01
        if (a >= x){
            println(i+1)
            break
        }
        a = floor(a)
    }
}