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

using namespace std;

double median(vector<int> &vec)
{
        sort(vec.begin(),vec.end());

        if(vec.size()%2 == 0)
        {
                return (vec[vec.size()/2] + vec[vec.size()/2 - 1])/2.0;
        }else{
                return vec[vec.size()/2];
        }
}

int main()
{
        vector<int> vec;
        int num,x;

        cin >> num;

        for(int i = 0;i < num;i++){
                cin >> x;
                vec.push_back(x);
        }

        cout << fixed << median(vec) << endl;

        return 0;
}