let split (s:string) = s.Split ' '

let f = split >> Seq.map int >> Seq.last
let g = split >> Seq.map int >> Seq.sort

let count =
    let m = stdin.ReadLine () |> f
    let sq = stdin.ReadLine () |> g

    let rec iter acc c =
        match (m - acc) with
        | i when i < 0 -> c - 1
        | i when i = 0 -> c
        | _ -> iter (acc + Seq.nth c sq) (c + 1)

    iter 0 0

count |> printfn "%d"