package main

import (
	"fmt"
	"sort"
)

func main() {
	solve275()
}

func solve275(){
	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.Println((float64(A[N/2])+float64(A[N/2-1]))/2)
	}
	return
}