let () =
  Scanf.scanf "%d %d\n" @@ fun h w ->
  let arr = Array.init (h*w) @@ fun _ -> Scanf.scanf "%d " @@ fun d -> d in
  let () = Array.fast_sort compare arr in
  for i = 0 to h - 1 do
    for j = 0 to w - 2 do
      Printf.printf "%d " arr.(i*w+j)
    done;
    Printf.printf "%d\n" arr.(i*w+w-1)
  done;