#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n;
    cin>>n;
    vector<int> v;
    for(int ctr1=0;ctr1<n;ctr1++){
        int t;
        cin>>t;
        v.push_back(t);
    }
    sort(v.begin(),v.end());
    if(n%2==1)
        cout<<v[n/2]<<endl;
    else
        printf("%.6f\n",((double)v[n/2]+v[n/2-1])/2);
    return 0;
}