open System open System.Collections.Generic [] module Cin = let read f = stdin.ReadLine() |> f let reada f = stdin.ReadLine().Split() |> Array.map f let readChars() = read string |> Seq.toArray let readInts() = readChars() |> Array.map (fun x -> Convert.ToInt32(x.ToString())) [] module Cout = let writer = new IO.StreamWriter(new IO.BufferedStream(Console.OpenStandardOutput())) let print (s: string) = writer.Write s let println (s: string) = writer.WriteLine s let inline puts (s: ^a) = string s |> println let solve() = let n = read int let a = reada float |> Array.sort let mid = n / 2 let ans = if n % 2 = 0 then (a.[mid - 1] + a.[mid]) / 2.0 else a.[mid] let ans = Math.Round(ans, 2, MidpointRounding.AwayFromZero) ans |> puts [] let main _ = try solve() with e -> printfn "%s" (e.ToString()) writer.Close() 0 // return an integer exit code