open System
open System.Text
open System.Collections.Generic

let solve s =
  s
  |> Seq.choose (fun c -> if Char.IsDigit c then c |> Char.GetNumericValue |> int |> Some else None)
  |> Seq.sum

[<EntryPoint>]
let main argv =
  let s = Console.ReadLine()
  printfn "%d" <| solve s

  //exit
  0