let _ =
	let n = Scanf.scanf "%d\n" (fun n -> n) in
    (
    match n with
    | 1 -> "Hello World"
    | 2 ->
    	let a, b = Scanf.scanf "%d\n%d\n" (fun a b -> a, b) in
        string_of_int @@ a + b
    | _ -> failwith "hoge"
    ) |> print_string