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


val () =
    let
        val n = readInt ()
        val k = readInt ()
        val ns = List.tabulate (n, fn _ => readInt ())
        val (min, max) =
            List.foldl
                (fn (x, (minAcc, maxAcc)) =>
                    (Int.min (x, minAcc), Int.max (x, maxAcc)))
                (2000, ~1)
                ns
        val ans = max - min
    in
        print (Int.toString ans ^ "\n")
    end