#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <math.h>
#include <cmath>
#include <limits.h>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <functional>
#include <stdio.h>
using namespace std;

long long MOD = 1000000007;

int main() {
    
    int N;
    cin >> N;
    vector<int> A(N);
    for ( int i = 0; i < N; i++ ) {
        cin >> A[i];
    }
    sort( A.begin(), A.end() );
    
    if ( N%2 ) { cout << A[N/2] << endl; }
    else { printf( "%f", ( static_cast<double>(A[N/2]) + static_cast<double>(A[(N-1)/2] ) ) / 2.0 ); }
    
    return 0;
}