#include "stdio.h"

double ary[1000] = {0};
int BubSort(double x[ ],int n);
int main(void);

int main(void){
    int n = 0;
    int i = 0;
    double numb = 0;
    scanf("%d",&n);
    for(i=0;i<n;i++){
        scanf("%lf",&ary[i]);
    }
    BubSort(ary,n);
    if((n % 2) == 0){
        numb = (ary[n/2-1] + ary[n/2])/2;
    }else{
        numb = ary[n/2];
    }
     printf("%.1f\n",numb);
     //   printf("%d\n",ary[0]);
    return 0;

}
int BubSort(double x[ ],int m){


    int i,j,temp;
    for(i=0;i<m-1;i++){
        for(j=m-1;j>i;j--)
            if(x[j-1]>x[j]){
                temp = x[j];
                x[j] = x[j-1];
                x[j-1] = temp;
            }
    }
    return 0;
}