#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

int main()
{
    int n; cin>>n;
    vector<int> a(n); for(int& e: a) cin>>e;
    sort(begin(a), end(a));

    if (n%2)
        cout<<a[n/2]<<endl;
    else
        cout<<(a[n/2-1]+a[n/2])*0.5<<endl;
}