#include <bits/stdc++.h>
using  namespace std;
int main(){

    int n;
    cin >> n;
    vector<double>v(n);
    if(n%2==0){
        for(int s=0;s<n;s++){
            cin >> v[s];
        }
        sort(v.begin(),v.end());
        cout << (v[n/2-1]+v[n/2])/2 << endl;



    }else{
        for(int s=0;s<n;s++){
            cin >> v[s];
        }
        sort(v.begin(),v.end());
        cout << v.at(n/2) << endl;



    }

    

}