import java.util.*
import javax.swing.plaf.SeparatorUI
import kotlin.math.ceil
import java.util.Queue as Queue1

fun main(args:Array<String>) {
    solve()
}

fun solve(){
    val n = readLine()!!.toLong()
    if(n <= 3L) println(n) else println((n - 3) * 5 + 3)
}