fun main(args : Array<String>) {
    val (a, v) = readLine()!!.split(" ").map { it.toInt() }
    val (b, w) = readLine()!!.split(" ").map { it.toInt() }
    val t = readLine()!!.toInt()

    if (v <= w) {
        println("NO")
        return
    }

    val diff = Math.abs(b - a)
    val fill = v - w

    println(if (Math.ceil(diff.toDouble() / fill.toDouble()).toInt() <= t) "YES" else "NO")
}