import java.util.*

fun main(arr:Array<String>) {
    val (amebaCount, move, totalTime) = readLine()!!.split(" ").map { it.toInt() }
    val amebaList = readLine()!!.split(" ").map { Ameba(it.toLong() - move.toLong() * totalTime, it.toLong() + move.toLong() * totalTime) }.sortedBy { it.from }.toMutableList()
    val minPos = amebaList.minBy { it.from }!!.from
    val amebaMap = mutableMapOf<Long, MutableList<Ameba>>()
    amebaList.map { (it.from - minPos) % move }.distinct().forEach { amebaMap[it] = mutableListOf() }
    var ans = 0.toLong()
    amebaMap.forEach {
        val key = it.key
        val list = amebaList.filter { (it.from - minPos) % move == key }.sortedBy { it.from }.toMutableList()
        for(i in list.lastIndex downTo 1) {
            if(list[i-1].to >= list[i].from) {
                list[i-1] = Ameba(list[i-1].from, list[i].to)
                list.removeAt(i)
            }
        }
        ans += list.map { (it.to - it.from) / move + 1 }.sum()
    }
    println(ans)
}

class Ameba(var from:Long, var to:Long)