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


fun quicksort [] = []
  | quicksort (h::tl) =
    let 
        val (s, b) =
            List.foldl
                (fn (x, (small, big)) =>
                    if x <= h then (x::small, big)
                    else (small, x::big))
                ([], [])
                tl
    in
        (quicksort s) @ [h] @ (quicksort b)
    end


fun printAns h w [] = ignore ()
  | printAns h w l =
    let
        val taked = List.take (l, w)
        val dropped = List.drop (l, w)
        val asString = String.concatWith " " (List.map (fn a => Int.toString a) taked)
    in
        (
          print (asString ^ "\n");
          printAns h w dropped
        )
    end
              

val () =
    let
        val h = readInt ()
        val w = readInt ()
        val aMatrix = List.tabulate (h, fn _ =>
                                           List.tabulate (w, fn _ => readInt()))
        val a_s = List.concat aMatrix
        val sorted = quicksort a_s
    in
        printAns h w sorted
    end