open Batteries
open BatPrintf

let scan fmt f =
  BatScanf.sscanf (read_line ()) fmt f

let scan_list cnv =
  read_line ()
  |> BatString.split_on_char ' '
  |> List.map cnv

let rec zip xs ys =
  match xs, ys with
  | [], _ -> []
  | _, [] -> []
  | x::xs, y::ys ->
    (x, y) :: zip xs ys

let (k, x) = scan "%d %d" BatTuple.Tuple2.make

let () =
  printf "%s\n"
    (if x <= k * 500 then
       "Yes"
     else
       "No")
