open System
open System.Collections
open System.Collections.Generic
open System.IO

[<EntryPoint>]
let main _ = 
    let S = Console.ReadLine().ToCharArray() 
            |> Array.map (fun c -> int c - int '0')

    let ans = 
        let under = S |> Array.sum
        let over  = S |> Array.where(fun x -> x = 0) 
                       |> Array.length
                       |> (*) 10
        under + over
    
    printfn "%i" ans

    0