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

using pint = pair< int, int >;
using ull = unsigned long long;

template< typename T >
void output( T&& range )
{
    for_each(
        begin( range ),
        end( range ),
        []( auto&& t )
        {
            cerr << t << endl;
        }
    );
}


int main()
{
    int n = 0;
    cin >> n;
    
    vector< int > v( n );
    
    for( auto&& i : v ) {
        cin >> i;
    }
    
    sort( begin( v ), end( v ) );
    
    if( n % 2 == 0 ) {
        cout << ( v[ ( n / 2 ) ] + v[ ( n / 2 ) - 1 ] ) / 2.0 << endl;
        return 0;
    }
    else {
        cout << v[ ( n / 2 ) ] << endl;
    }
}