#include <bits/stdc++.h>
#define FOR(i,bg,ed) for(ll i=(bg);i<(ed);i++)
#define REP(i,n) FOR(i,0,n)
#define MOD 1000000007
#define int long long
using namespace std;
typedef long long ll;
const int INF = 1e9;

int N;
int A[1010];

signed main()
{
    cin >> N;
    REP(i,N) 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;
    }
}