package main

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

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