#include<stdio.h>
#include<algorithm>
using namespace std;
int b[1100];
int main(){
	int a;scanf("%d",&a);
	for(int i=0;i<a;i++)scanf("%d",b+i);
	std::sort(b,b+a);
	if(a%2)printf("%d\n",b[a/2]);
	else printf("%f\n",0.5*(b[a/2]+b[a/2-1]));
}