#include<iostream>
#include<iomanip>
#include<cmath>
#include<string>
#include<algorithm>
#include<vector>
#include<math.h>
#include<stack>
using namespace std;
int main(void){
    int N; cin >> N;
    double A;
    vector<double> v;
    for(int i = 0; i < N; i++){
        cin >> A;
        v.push_back(A);
    }
    sort(v.begin(), v.end());
    if(N % 2 != 0){
        cout << v[(N-1) / 2] << endl;
    }else{
        cout << (v[(N-1) / 2] + v[(N-1) / 2 + 1]) / 2 << endl;
    }
    return 0;
}