#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    cin>>n;
    int a[205];
    for (int i =0;i<n;i++) cin >>a[i];
    for (int i =1;i<=n-1;i++)
    {
        for (int j=0;j<=n-1-i;j++)
        {
            if(a[j] > a[j+1]) swap(a[j],a[j+1]);
        }
    }

    if(n%2==0)
    {
        printf("%.1f", ((a[n/2] + a[n/2-1])/2.0));
    }
    else
    {
        printf("%.1f", (a[n/2])/1.0);

    }
    


    return 0;
}

/**************************************************************
	Problem: 1233
	User: mariooo
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/