val D = "1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991"

fun f(n:Int): String {
    tailrec fun iter(i: Int, c: Int, sb: StringBuilder) {
        if (i>=0) {
            val t = n*D.slice(i..i).toInt()+c
            sb.insert(0,(t%10).toString())
            return iter(i-1, t/10, sb)
        } else {
            if (c!=0) { sb.insert(0,c.toString()) }
        }
    }
    val sb = StringBuilder(D.length+2)
    val t = n*D.slice(D.length-1..D.length-1).toInt()
    sb.insert(0,(t%10).toString())
    iter(D.length-2,t/10,sb)
    if (sb.length==D.length) sb.insert(0,"0.") else sb.insert(sb.length-D.length,".")
    return sb.toString()
}

fun g(m: Int, n: Int): String {
    fun f(a: Int, b: Int, c: Int) = if ((a+b+c)%10>9) 1 else 0
    tailrec fun iter(i: Int, c: Int, c1: Int, c2: Int, t2: Int, sb: StringBuilder) {
        if (i>=0) {
            val t = D.slice(i..i).toInt()
            val t1 = n*t+c1
            sb.insert(0,((t2+t1+c)%10).toString())
            iter(i-1, f(t2,t1,c), t1/10, (m*t+c2)/10, m*t+c2, sb)
        } else {
            sb.insert(0,(t2+c1+c).toString())
        }
    }
    val sb = StringBuilder(D.length+3)
    var t = D.slice(D.length-1..D.length-1).toInt()
    var t1 = n*t
    val t2 = m*t
    val c1 = t1/10
    val c2 = t2/10
    sb.insert(0,(t1%10).toString())

    t = D.slice(D.length-2..D.length-2).toInt()
    t1 = n*t+c1
    sb.insert(0,((t1+t2)%10).toString())
    iter(D.length-3, f(t2,t1,0), t1/10, (m*t+c2)/10, m*t+c2, sb)

    sb.insert(sb.length-D.length,".")
    return sb.toString()
}

fun main(args: Array<String>) {
    val s = readLine()!!
    when (s.length) {
        1 -> println(f(s.toInt()))
        2 -> println(g(s.slice(0..0).toInt(), s.slice(1..1).toInt()))
        else -> println(D.slice(0..1).plus(".").plus(D.slice(2..D.length-1)))
    }
}