#include<bits/stdc++.h>
#define endl '\n'
#define MAXN 2000
using namespace std;

int main()
{
    int n, a[MAXN];
    cin >> n;
    for(int i = 0; i < n; i++)
    {
        cin >> a[i];
    }

    sort(a, a + n);
    if(n % 2 == 0)
    {
        cout << (a[n / 2] + a[n / 2 - 1]) / 2.0 << endl;
    }
    else
    {
        cout << a[n / 2] << endl;
    }


    return 0;
}