#include "bits/stdc++.h"
using namespace std;

#define REP(i, n) for(int i=0; i<(n); i++)

int N,T;
signed main()
{
    cin >> N;
    vector<int> A(N);
    REP(i,N) cin >> A[i];
    if (N % 2) {
        cout << A[N/2+1] << endl;
    } else {
        cout << (A[N/2] + A[N/2-1]) * 0.5 << endl;
    }
    return 0;
}