#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cmath>

#define rep(i,n) for(i=0; i<n; ++i)
#define in(a) cin >> a
#define out(a,b) cout << a << b
using namespace std;
using lint = long long;

int main(void){
    int i, j, n, m, k, cnt = 0;
    float med;
    in(n);
    vector<int> A(n);
    rep(i,n)    in(A[i]);
    sort(A.begin(), A.end());
    if(n%2==0){
        med = (A[n/2]+A[n/2-1])/2.0;
        out(med,endl);
    }
    else    out(A[n/2],endl);

    return 0;
}