#include<stdio.h>
#include<algorithm>

using namespace std;

int main(void){
    int n,i,a[1000],ans;
    scanf("%d",&n);
    for(i=0; i<n; i++){
        scanf("%d",&a[i]);
    }
    sort(a,a+n);
    if(n%2==1){
        printf("%d\n",a[n/2]);
    }else{
        ans = a[(n/2)-1]+a[n/2];
        printf("%lf\n",(double)(ans)/2);
    }
    return 0;
}