Scanf.scanf "%d %d %s" (fun n m s ->
    let mat = Array.make_matrix (n + 1) (n + 1) 1 in
    mat.(n).(0) <- 0;
    let rec loop i x y =
        if i = m then mat else
            let x = if s.[i] = 'L' then x - 1 else if s.[i] = 'R' then x + 1 else x in
            let y = if s.[i] = 'D' then y + 1 else if s.[i] = 'U' then y - 1 else y in
            let () = mat.(y).(x) <- 0 in
            loop (i + 1) x y
    in
    Array.iter (fun a ->
        Array.iter (Printf.printf "%d ") a; print_newline ()
            ) @@ loop 0 0 n 

)