#include<iostream>
#include<cstdio>
#include<vector>
#include<algorithm>
using namespace std;
int main(){
    int N;
    float x;
    vector<float> a;
    cin >> N;
    for(int i=0;i<N;i++){
        cin >> x;
        a.push_back(x);
    }
    sort(a.begin(),a.end());
    if(!(N%2)){
        printf("%.1f",(a[N/2]+a[N/2-1])/2);
    }
    else{
        printf("%.1f",a[N/2]);
    }
    return 0;
}