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

int main(){
    int N,in;
    vector<int> v;

    cin >> N;
    while(cin >> in) v.push_back(in);
    sort(v.begin(),v.end());
    if(N%2!=0) cout << v[N/2] << endl;
    else cout << (double)(v[N/2]+v[N/2-1])/2.0 << endl;

    return 0;
}