fun main(args: Array<String>) {
    val (a, b, c, d) = readLine()!!.split(" ").map(String::toInt)
    val flag = (abs(c - a) <= d) || (abs(b - a) <= d && abs(c - b) <= d)
    println(if (flag) "Yes" else "No")
}

fun abs(i: Int): Int = if (i < 0) i*-1 else i