let () =
  Scanf.scanf "%d %f %f" @@ fun n t a ->
  let hs = Array.init n (fun i -> i+1, Scanf.scanf " %f" @@ fun x -> x) in
  Array.fold_left (fun (u, v) (i, h) ->
    let b = abs_float (t -. h *. 0.006 -. a) in
    if b < v then (i, b) else (u, v)) (-1, 1010101010.0) hs
  |> fst |> Printf.printf "%d\n"
