#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,a[200];
	float v;
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	for(int i=1;i<n;i++){
		for(int j=1;j<=n-i;j++){
			if(a[j]<a[j+1]) swap(a[j],a[j+1]);
		}
	}
	if(n%2==1){
		v=a[n/2+1]*1.0;
	}else{
		v=(a[n/2]+a[n/2+1])*1.0/2;
	}
	printf("%.1f\n",v);
	
	

	return 0;
}

/**************************************************************
	Problem: 1233
	User: lidongcheng
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/