// Learn more about F# at http://fsharp.net
// See the 'F# Tutorial' project for more help.
open System
open System.Text.RegularExpressions

let rec nwd (l:int, m:int) =
    printfn "%d %d" l m
    match l,m with
    | (0, m) -> m
    | (l, m) -> nwd(l%m ,m)

let StringToList(s: String) =
    let array = s.ToCharArray() |> List.ofArray
    array

let rec createMianownikExec(cz_ok: List<char>, cz_nok: List<char>, r: String) =
    match cz_ok, cz_nok with
    | [],[] -> String.Concat(r,"")
    | [],h::t -> createMianownikExec(cz_ok, t, String.Concat(r,"0"))
    | h::t,_ -> createMianownikExec(t, cz_nok, String.Concat(r,"9"))

let createMianownik(cz_ok: String, cz_nok: String) =
    createMianownikExec(StringToList(cz_ok), StringToList(cz_nok),"")

let regExp(input, pattern) =
    let r = new Regex(pattern)
    r.Matches(input)

let readGroups(input, pattern) =
    ((new Regex(pattern)).Match(input)).Groups

let if_null(input : String, default_value) =
    match input with
    | "" -> default_value
    | _ -> int(input)

let fract(n: System.String) =
    let pattern = "0[,|.]([0-9]+)?(\(([0-9]+)\))"
    //printfn "%A" (readGroups(n, pattern))
    if (regExp(n, pattern)).Count > 0 then
        let groups = (readGroups(n, pattern))
        let cz_ok = groups.Item(3).ToString()
        let cz_nok = groups.Item(1).ToString()
        let cz_wsp = String.Concat(cz_nok, cz_ok)
        let l1 = int(cz_wsp)
        let l2 = if_null(cz_nok, 0)
        if (l1 = 0 && l2 = 0) then
            "ERR"
        else
            let licz = l1 - l2
            let mian = int(createMianownik(cz_ok, cz_nok))
            let d = nwd(licz, mian)
            printfn "%d/%d" (licz/d) (mian/d)
            n
    else
        "ERR"

[<EntryPoint>]
let main argv =
    //let num = System.Console.ReadLine()
    printfn "%A" (fract("0.78(5)"))
    0 // return an integer exit code