# include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
	float a[110000];
	cin>>n;
	
	for(int i=1;i<=n;i++){
		cin>>a[i];
	} 
	sort(a+1,a+1+n);
//	for(int i=1;i<=n;i++){
//		cout<<a[i]<<" ";
//	}
	if(n%2==1){
		printf("%.1f",a[n/2+1]);
	}
	
	else{
		float p=float(a[n/2]+a[n/2+1]);
		printf("%.1f",&p);
	}
	


    return 0;
}

/**************************************************************
	Problem: 1233
	User: caiqiaoxi
	Language: C++
	Result: Wrong Answer
****************************************************************/