import kotlin.math.abs
import kotlin.math.ceil

fun main(args: Array<String>) {
    p75()
}

fun p75() {
    val (x, y, l) = (1..3).map { readLine()!!.toInt() }

    val answer = ceil(abs(x).toDouble() / l).toInt() + ceil(abs(y).toDouble() / l).toInt() + when (y) {
        in Int.MIN_VALUE..-1 -> 2
        else -> when (x) {
            0 -> 0
            else -> 1
        }
    }

    println(answer)
}