#include<bits/stdc++.h>
using namespace std;
int main(){
	int a[15]={0},n,i,j,h;
	cin>>n;
	for(i=0;i<n;i++){
		cin>>a[i];
    }
	for(i=0;i<4;i++){
		for(j=0;j<n-1;j++){
			if(a[j]>a[j+1]){
				swap(a[j],a[j+1]);
			}
		}
	}
	h=a[n/2-1]+a[n/2];
	if(n%2==1){
		cout<<a[(n-1)/2];
	}else{
		printf("%.1f",h/2.0);
	}
}
/**************************************************************
	Problem: 1233
	User: lvrenxiang
	Language: C++
	Result: Wrong Answer
****************************************************************/