#include <iostream>
#include <sstream>
#include <math.h>
#include <stack>
#include <set>
#include <algorithm>
#include <string>
#include <queue>
#include <stack>
#include <map>
#include <cstdio>
#include <vector>
using namespace std;

#define INF (1 << 30)
#define INFLL (1LL << 60)

int main() {
	int n;
	float A[1001];
	cin >> n;
	for(int i = 0;i < n;i++){
		cin >> A[i];
	}
	sort(A,A + n);
	if(n % 2 == 1){
		cout << A[n/2] << endl;
	}else{
		cout << (A[n/2-1] + A[n/2]) / 2 << endl;
	}
	return 0;
}