#include<bits/stdc++.h>
using namespace std;
int main(){
int n,i,l,a[100];
float x;
cin>>n;
for(i=0;i<n;i++) {
	cin>>a[i];
}
for(l=n-1;l>=1;l--) {
	for(i=0;i<l;i++) {
		if(a[i]>a[i+1]) {
			swap(a[i],a[i+1]);
        }
    }
}
if(n%2==0) {
	x=(a[n/2]+a[n/2-1])/2.0;
}else{
	x=a[n/2];
}
printf("%.1f",x);
return 0;
}

/**************************************************************
	Problem: 1233
	User: 12345678
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/