#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    vector<double> d(n);
    for(int i=0;i<n;i++){
        cin>>d[i];
    }
    sort(d.begin(),d.end());
    cout<<(n%2==1?d[n/2]:(d[n/2]+d[n/2-1])/2)<<endl;
}