import java.util.*

fun main() {
    val sc = Scanner(System.`in`)
    val n = sc.nextLong()

    println(calc(n))
}

fun calc(n: Long): Long {
    var cnt = 0L
    (1L..n).forEach { a ->
        (1..n / a).forEach { b ->
            val c = n - (a*b)
            if (a * b + c == n && c > 0) cnt++
        }
    }
    return cnt
}