let ``No.51 やる気の問題``() =

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

  let rec loop w n =
    match n with
    | 1 ->(w / n)
    | _ -> w - (w / (n * n))
          |> fun arg -> loop arg (n-1)

  loop w d
  |> stdout.WriteLine

``No.51 やる気の問題``()