#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
using namespace std;

int main(){
    int N;
    cin>>N;
    vector<int> V;
    for(int i=0;i<N;i++){
        int a;
        cin>>a;
        V.push_back(a);
    }
    sort(V.begin(),V.end());
    if(N%2){
        cout<<V[N/2]<<endl;
    }else{
        cout<<fixed;
        cout.precision(1);
        cout<<(V[N/2]+V[N/2-1])/2.0<<endl;
    }
    return 0;
}