let ``No.51 やる気の問題``() =
  let rec loop y x=
    match y with
    | 1 -> x
    | _ -> x - int ( decimal(x) / ( decimal y * decimal y) )
          |> int
          |> loop (y-1)

  let w = stdin.ReadLine() |> int
  let d = stdin.ReadLine() |> int

  loop d w
  |> stdout.WriteLine

``No.51 やる気の問題``()