#define _USE_MATH_DEFINES
 
#include <iostream>
#include <iomanip>
#include <sstream>
 
#include <algorithm>
#include <cmath>
 
#include <string>
//#include <array>
#include <list>
#include <queue>
#include <vector>
#include <complex>
#include <set>
#include <map>
 
/////////
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)
#define P(p) cout<<(p)<<endl;
 
#define PII pair<int,int>
/////////
typedef long long LL;
typedef long double LD;
/////////
using namespace::std;
/////////

int main(void){
    std::cin.tie(0); 
    std::ios::sync_with_stdio(false);
    std::cout << std::fixed;//
    //cout << setprecision(16);//
	
	int N;
	cin >> N;
	vector<int> v(N);
	rep(i,N){
		cin >> v[i];
	}
	sort( v.begin(), v.end() );

	if( N%2 ){//in N==1
		P( v[N/2] );
		return 0;
	}

	double L,R,ans;
	L = v[N/2-1];
	R = v[N/2];
	ans = (L+R)/2;
	P( ans );
	return 0;
}