let ``No.5 数字のブロック`` () =
    let L = int <| stdin.ReadLine()
    let M = int <| stdin.ReadLine()
    let N =
        stdin.ReadLine().Split(' ')
        |> Seq.map int
        |> Seq.sort
        |> Seq.toList
    let rec f s c = function
        | [] -> c
        | x::xs ->
            if s >= L then c
            else f (s+x) (c+1) xs
    printfn "%d" ((f 0 0 N)-1)
``No.5 数字のブロック`` ()