#include<iostream>
#include<algorithm>
using namespace std;
int main(){
    int num;
    cin>>num;
    int*data = new int(num);
    for(int i=0; i<num;i++){
        cin>>data[i];
    }
    sort(data,data+num);
    if(num%2 == 1){
        cout<<(double)data[num%2+1];
    }else{
        cout<<((double)data[num%2]+(double)data[num%2+1])/2;
    }
    return 0;
}