#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define itn int
#define rep2(i,a,n) for(int i = (a);i < (n);i++)
#define rep(i,n) rep2(i,0,n)
using P = pair<int,int>;

int main(void){
    int n;
    cin >> n;
    double a[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;
    
}