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

using namespace std;

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