#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;
using ll =  long long ;
using P = pair<int,int> ;
using pll = pair<ll,ll>;
constexpr int INF = 1e9;
constexpr ll LINF = 1e18;
constexpr int MOD = 1000000007;

int main(){
    int n;
    cin >> n;
    vector<int> a(n);
    rep(i,n) cin >> a[i];
    sort(a.begin(),a.end());
    if(n%2==1){
        cout << a[n/2] << endl;
    }else{
        cout << setprecision(10) << (double)(a[n/2] + a[n/2-1])/2 << endl;
    }
    return 0;
}