let rec compress n list =
    match list with
    | [] -> []
    | [ c ] when n = 1 -> [ c ]
    | [ c ] -> [ c; string n ]
    | x :: xs when x = List.head xs -> compress (n + 1) xs
    | x :: xs when n = 1 -> x :: compress 1 xs
    | x :: xs -> x :: string n :: compress 1 xs

open System

[<EntryPoint>]
let main _ =
    Console.ReadLine()
    |> Seq.toList
    |> List.map string
    |> compress 1
    |> String.concat ""
    |> Console.WriteLine

    0