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



fun readStr () =
    let
        fun scan reader stream = SOME (StringCvt.splitl (not o Char.isSpace) reader (StringCvt.skipWS reader stream))
    in
        valOf (TextIO.scanStream scan TextIO.stdIn)
    end

fun intPow (x, y) =
    let
        fun loop n =
            if n = 0 then 1
            else x * loop (n - 1)
    in
        loop y
    end


val () =
    let
        val l = readInt ()
        val n = readInt ()
        val s_s = List.tabulate (n, fn _ => readStr ())

        val ans =
            List.foldl
                (fn (s, acc) =>
                    acc + intPow(2, l - String.size s))
                0
                s_s
    in
        print (Int.toString ans ^ "\n")
    end