#include <cstdio>
#include <algorithm>
#include <vector>
#define REP(i,n) for (int i = 0; i < n; i++)
using namespace std;

int main() {
    int n;
    scanf("%d", &n);
    vector<int> v(n);
    REP(i,n) scanf("%d", &v[i]);
    sort(v.begin(), v.end());
    if (n%2) {
        printf("%d\n", v[n/2]);
    } else {
        printf("%f\n", (v[n/2-1]+v[n/2])/2.0);
    }
}