package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strconv"
)

func main() {
	var n int
	fmt.Scan(&n)
	a := make([]int, n)
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	for i := range a {
		sc.Scan()
		a[i], _ = strconv.Atoi(sc.Text())
	}
	sort.Ints(a)
	if len(a)%2 == 0 {
		fmt.Println(float64(a[len(a)/2-1]+a[len(a)/2]) / float64(2))
	} else {
		fmt.Println(a[len(a)/2])
	}
}