Scanf.scanf "%d %d" (fun n k ->
    let rec gcd a b = if b = 0 then a else gcd b (a mod b) in
    let a = Array.init n (fun _ -> Scanf.scanf " %d" (fun a -> a)) in

    let rec loop i mx gc =
        if i = n then mx >= k && (mx - k) mod gc = 0 else
            loop (i + 1) (max mx a.(i)) (gcd gc a.(i))
    in
    loop 1 a.(0) a.(0) |> (fun b -> print_endline @@ if b then "POSSIBLE" else "IMPOSSIBLE")
)