#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(void){
    // Here your code !
    int n;
    vector<int> k;
    cin >> n;
    while( n-- ) {
        int a;
        cin >> a;
        k.push_back(a);
    }
    
    sort(k.begin(), k.end());
    
    if (k.size() % 2 == 0) {
        cout << (k[k.size() / 2] + k[k.size() / 2 - 1]) / 2.0;
    }
    else {
        cout << k[k.size() / 2];
    }
    return 0;
}