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

using namespace std;

int main(void){
    int N; cin>>N;
    vector<int> a(N);
    for(int i=0;i<N;i++) cin>>a[i];
    sort(a.begin(),a.end());
    if(N%2) cout<<a[N/2]<<endl;
    else{
        double m=(a[N/2-1]+a[N/2])/2.0;
        cout<<m<<endl;
    }
}