let split (s:string) = s.Split ' '

let snd = split >> Array.map float >> fun (a:float[]) -> a.[1]
let average = split >> Seq.map float >> Seq.average

let judge =
    match (stdin.ReadLine () |> snd,
           stdin.ReadLine () |> average) with
    | (a, b) when a = b -> "YES"
    | _ -> "NO"

judge |> printfn "%s"