#define _USE_MATH_DEFINES
#include<stdio.h>
#include<string>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include<iomanip>
using namespace std;



int main(){

int n;
cin>>n;
int g[1004]={};
for(int i=0;i<n;i++)
	cin>>g[i];
sort(g,g+n);
double ans;
if(n%2){
	cout<<g[n/2]<<endl;
}
else{ans=((double)g[n/2]+(double)g[n/2-1])/2;
	cout<<ans<<endl;
}
	return 0;
}