let () =
    seq { for i = 0 to 2 do
            let h, w = stdin.ReadLine ()
                    |> fun s -> s.Split()
                    |> fun arr -> (int arr.[0], int arr.[1])
            let c = 'A' |> int |> fun x -> x + i |> char
            yield (c, h, w) }
    |> Seq.sortBy (fun (_, h, w) -> (-h, w))
    |> Seq.iter (fun (c, _, _) -> printfn "%c" c)