let () =
    let s = read_line () |> Str.split (Str.regexp "") in
    let ans = List.fold_left (fun (a, b, c) elt ->
            match elt with
            | "a" -> (a + 1, b, c)
            | "b" -> (a, b + 1, c)
            |  _  -> (a, b, c + 1)
        ) (0, 0, 0) s
    in
    if ans = (1, 1, 1) then print_endline "Yes"
    else print_endline "No"
