#include <iostream>
#include <algorithm>
#include <functional>
#include <string>
#include <climits>
#include <vector>
#include <numeric>
#include <complex>
#include <map>
#include <bitset>
#include <stack>
#include <queue>
using namespace std;

//#define __int64 long long
#define long __int64
#define REP(i,a,b) for(int i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)
const int Vecy[4] = {0,-1,0,1};
const int Vecx[4] = {1,0,-1,0};
const int modd = 1000000007;

int main(){
	int n;
	int a[1000];
	double kekka;
	cin >> n;
	rep(i,n){
		cin >> a[i];
	}
	
	sort(a, a+n);
	
	if(n % 2 == 1){
		cout << a[n/2] << endl;
	}else{
		kekka = ((double)a[n/2-1] + a[n/2]) / 2;
		cout << kekka << endl;
	}
	
    return 0;
}