import Foundation

func readInt() -> [Int]{
    return readLine()!.split(separator:" ").map{Int($0)!}
}

let A = readInt()
let B = readInt()
let c = Int(readLine()!)!

if(A[1] <= B[1]){
  print("NO")
}else{
  if(abs(A[0] - B[0]) < c * (A[1] - B[1])){
    print("YES")
  }else{
    print("NO")
  }
}