#include<bits/stdc++.h>
using namespace std;
int main(){
	int i,j,n,a[155]={ },x,y;
	float h,z;
	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=n/2;
		y=x-1;
		z=a[x]+a[y];
		h=z/2.0;
	}
	else{
		h=a[n/2];
	}
	printf("%.1f",h);
}
/**************************************************************
	Problem: 1233
	User: zengyixuan
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/