open System

let judgeEto inseq =
    let maxNum = int (ceil (float (Seq.length inseq) / 2.))
    inseq |> Seq.groupBy id |> Seq.map (fun (key, gseq) -> Seq.length gseq) |>
    Seq.max |> (fun nmax -> nmax <= maxNum)

let N = Console.ReadLine () |> int
seq { for _ in 1..N -> Console.ReadLine ()} |> Seq.toList |> Seq.ofList |>
judgeEto |>
(fun result -> if result then "YES" else "NO") |> printfn "%s"