let main () =
  let (a, b,c ,d) = Scanf.scanf "%d %d %d %d" (fun a b c d -> (a, b, c, d)) in
  if (abs @@ (-) a b <= d && abs @@ (-) b c <= d) || abs @@ (-) a c <= d then
    print_string "Yes\n"
  else
    print_string "No\n"

let () = main ()
