import scala.math._

object Main extends App {
    val tempList: Seq[Seq[String]] = {
      for(line <- io.Source.stdin.getLines()) yield {
        line.split(' ').toSeq
      }
    }.toSeq

    val aInfo: Seq[Int] = tempList(0).map(_.toInt)
    val bInfo: Seq[Int] = tempList(1).map(_.toInt)
    val timeLimit: Int = tempList(2)(0).toInt

    //AとBの速度差: -ならその時点でNO
    val diffSpeed: Int = aInfo(1) - bInfo(1)
    //T秒で縮められる距離
    val diffInSec: Int = diffSpeed*timeLimit
    //AとBの距離
    val distance: Int = abs(aInfo(0) - bInfo(0))

    if(diffInSec >= distance) println("YES")
    else println("NO")
}