# include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    float a[110000];
    cin>>n;
     
    for(int i=1;i<=n;i++){
        cin>>a[i];
    } 
    sort(a+1,a+1+n);
//  for(int i=1;i<=n;i++){
//      cout<<a[i]<<" ";
//  }
    if(n%2==1){
        printf("%.1f",a[n/2+1]);
    }
     
    else{
        float p=float(a[n/2]+a[n/2+1]);
        printf("%.1f",p/2);
    }
     
 
 
    return 0;
}
/**************************************************************
	Problem: 1233
	User: linmiaoling
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2384 kb
****************************************************************/