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