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

    var tmpA = a
    var tmpB = b
    val moveToRight = a < b

    for (i in 0 until t) {
        if (moveToRight) {
            tmpA += v
            tmpB += w

            if (tmpB <= tmpA) {
                println("YES")
                return
            }
        } else {
            tmpA -= v
            tmpB -= w

            if (tmpA <= tmpB) {
                println("YES")
                return
            }

        }
    }
    println("NO")
}
