open System
let R T = stdin.ReadLine()|> T
let RS T = stdin.ReadLine().Split()|>Array.map T
let R2 T U = RS string|>fun c-> (c.[0]|>T),(c.[1]|>U)
let R3 T U V = RS string|>fun c-> (c.[0]|>T),(c.[1]|>U),(c.[2]|>V)
let R4 T U V W = RS string|>fun c-> (c.[0]|>T),(c.[1]|>U),(c.[2]|>V),(c.[3]|>W)
let R5 T U V W X = RS string|>fun c-> (c.[0]|>T),(c.[1]|>U),(c.[2]|>V),(c.[3]|>W),(c.[4]|>X)
let outl s = stdout.WriteLine(s|>string)
let outsep ls = stdout.WriteLine(String.concat " " (ls|>Array.map string))
let outsepl ls = stdout.WriteLine(String.concat "\n" (ls|>Array.map string))
let Mod = (1e9|>int64)+7L
[<EntryPoint>]
let main argv =
    RS int|>Array.distinct|>Array.length|>fun c->if c=2 then "Yes" else "No"
    |>outl
    0
    