#include<bits/stdc++.h>
#define rep(i,a,n) for (int i = a;i < n;i++)
#define per(i,n,a) for (int i = n-1;i >= a;i--)
using namespace std;

int main() {
    int n; cin >> n;
    vector<int> a(n);
    rep(i,0,n){
        cin >> a[i];
    }
    sort(a.begin(),a.end());
    if(n%2 == 1) {
        cout << a[n/2] << endl;
    }else{
        cout << (a[n/2-1] + a[n/2]) / 2.0 << endl;
    }
}