fun main(){
    val x = readLine()!!.toInt()
    val y = readLine()!!.toInt()
    val l = readLine()!!.toInt()
    var cnt = 0
    if(y < 0){
        cnt += 2
    }else if(x != 0){
      cnt ++  
    }
    cnt += Math.abs(x) / l
    if(x % l != 0) cnt++
    cnt += Math.abs(y) / l
    if(y % l != 0) cnt++
    println(cnt)
}