#include <bits/stdc++.h>
using namespace std;
int main(){
	int a[100],i,j,n,x,y;;
	float h=0;
	cin>>n;
	for(i=0;i<n;i++){
		cin>>a[i];
	}
	for(i=1;i<n;i++){
		for(j=0;j<n-i;j++){
			if(a[j]>a[j+1]){
				swap(a[j],a[j+1]);
			}
		}
	}
	if(n%2==0){
		x=a[n/2];
		y=a[x-1];
		h=(x+y)*1.0/2;
	} else{
		h=a[n/2];
	}
	printf("%.1f",h);
}
/**************************************************************
	Problem: 1233
	User: yangjunwen
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/