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