#include<bits/stdc++.h>
#define ll long long int
#define repv(x,y) for(auto&x:(y))
#define rep(x,z,y) for(long long int x=(z);x<(y);x++)
using namespace std;


int main()
{
	ll N;
	cin>>N;
	vector<ll>v(N);
	repv(elem,v)
	cin>>elem;
	sort(v.begin(),v.end());
	if(N&1)
	cout<<v[N/2]<<endl;
	else
	cout<<((double)v[N/2]+(double)v[N/2-1])/2<<endl;
    return 0;
}