fun readInt () =
    valOf (TextIO.scanStream (Int.scan StringCvt.DEC) TextIO.stdIn)



fun insertionSort l =
    let
        fun insert x [] = [x]
          | insert x (y::ys) = if x <= y then x::y::ys
                               else y::(insert x ys)
    in
        foldl (fn (x, acc) => insert x acc) [] l
    end

val () =
    let
        val l = readInt ()
        val n = readInt ()
        val w_s = List.tabulate (n, fn _ => readInt ())
        val sorted = insertionSort w_s

        fun findAns [] _ = 0
          | findAns (h::tl) space = if h <= space then 1 + findAns tl (space - h)
                                  else 0 

        val ans = findAns sorted l
    in
        print ((Int.toString ans) ^ "\n")
    end