#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

int main(){
    int n;
    cin>>n;

    vector<int> v(n);

    for (int i=0; i <n; i++) {
        cin >> v[i];
    }

    sort(v.begin(), v.end());

    if (n%2 == 0) {
        cout<<(v[n/2] + v[n/2 -1])/2.0 << endl;
    } else {
        cout<<v[n/2]<<endl;

    }

    return(0);
}