#include<iostream>
#include<string>
#include<string.h>
#include<algorithm>
#include<stdio.h>
#include<cmath>
#include<vector>
#include<utility>
#include<queue>
#include<stack>
#include<stdlib.h>
#define FOR(i, a, b) for(int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(int i=(a);i>=(b);i--)
#define MOD 1000000007

using namespace std;


int main(void) {
	int n;
	double a[1001];
	cin >> n;
	FOR(i, 1, n) {
		cin >> a[i];
	}
	sort(a, a + n + 1);
	if (n % 2 == 1) {
		printf("%.1lf\n", a[n / 2 + 1]);
	}
	else {
		printf("%.1lf\n", (a[n/2]+a[n/2+1])/2);
	}
	return 0;
}