[<EntryPoint>]
let main argv =

    printf "Iveskite Fibinacio skaiciu sekos ilgi: "
    let ilgis = System.Console.ReadLine() |> int

    let rec fib n1 n2 a =  // 3, 5 -> 5, 8
        if a > 0 then
            printfn "%d : %d" (ilgis-a) (n1)
            fib (n2) (n1+n2) (a-1)
            else
                n1

    let sk = fib 0 1 ilgis

    printfn "%d narys yra: %d \n" ilgis sk