let () =
  let rec loop () = 
    let a, op, b = Scanf.scanf "%d %c %d\n" (fun a b c -> a,b,c) in
    match op with
      | '?' -> ()
      | '+' -> Printf.printf "%d\n" (a+b); loop ()
      | '-' -> Printf.printf "%d\n" (a-b); loop ()
      | '*' -> Printf.printf "%d\n" (a*b); loop ()
      | '/' -> Printf.printf "%d\n" (a/b); loop ()
      | _   -> ()
  in loop ()