open Printf;;

let rec ler_floats n acc = 
  if n >= 0 then ler_floats (n-1) ((read_float ()) :: acc) else List.rev acc;;

let grau = read_int () ;;
let x = read_float () ;;
let coefs = ler_floats grau [];;

let rec horner_list gr x
 lv acc =
    match lv with 
      [] -> acc
    | el::li  -> 
      horner_list gr x li (x *. acc +. el)
;;

let res = horner_list grau x coefs 0.0 in
(printf "%.3f\n" res);;

(* versão com calculo a medida da leitura dos coeficientes *)
(*
let rec horner gr x n pi =
    if  n> gr then pi
    else 
      let v = read_float () in
      let p =  x*.pi +. v in
	horner gr x (n+1) p;;

let p_x= horner grau x 0 0.0 in 
  (printf "%.3f\n" p_x);;
*)