let () =
  let rec simple_calculator ()=
    let a, op, b = Scanf.sscanf (read_line()) "%d %c %d" (fun a op b -> a,op,b) in
    match op with
      |'+' -> print_int (a + b);print_string "\n"; simple_calculator ();
      |'-' -> print_int (a - b);print_string "\n"; simple_calculator ();
      |'*' -> print_int (a * b);print_string "\n"; simple_calculator ();
      |'/' -> print_int (a / b);print_string "\n"; simple_calculator ();
      |_ -> ();
  in
  simple_calculator ();
;;
