package main

import (
	"fmt"
	"sort"
)

func main() {
	var N int
	fmt.Scan(&N)
	A := make([]int, N)
	for i := 0; i < N; i++ {
		fmt.Scan(&A[i])
	}
	sort.Ints(A)
	if N%2 == 1 {
		fmt.Println(A[N/2])
	} else {
		fmt.Printf("%.1f\n", float64(A[N/2]+A[N/2-1])/2.0)
	}
}