#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,a[15],i,j=0;
	float h=0;
	cin>>n;
	for(i=0;i<n;i++){
	    cin>>a[i];	
	}
	for(i=n-1;i>0;i--){
        for(j=0;j<i;j++){
            if(a[j]>a[j+1]){
                swap(a[j],a[j+1]);
            }
        }
    }
	if(n%2==0){
	   h=(a[n/2]+a[n/2-1])/2.0;	
	}	
	if(n%2==1){
	   h=a[n/2];	
	}	
	printf("%.1f",h);
	return 0;
}
/**************************************************************
	Problem: 1233
	User: lijinkai
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2076 kb
****************************************************************/