#include <bits/stdc++.h>
using namespace std;

signed 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&1)cout<<v[n/2]<<endl;
    else cout<<(double)(v[n/2]+v[n/2-1])/2<<endl;
}