let op x = match x with
    '+' -> (+)
  | '-' -> (-)
  | '*' -> ( * )
  | '/' -> (/)
  | _ -> (fun x -> fun x -> x);;

let rec read () =
  let f x y z = match y with
    '?' -> ()
    | y -> Printf.printf "%d\n" ((op y) x z);read ()
  in
  Scanf.scanf "%d %c %d\n" f;;

 let () = read ();;