#include <stdio.h>
#include <stdlib.h>

int compare(const void *a, const void *b)
{
	return *(short *)a - *(short *)b;
}

int main(void)
{
	short n,*a,i;
	double ans;
	scanf("%hd",&n);
	a = (short *)malloc(sizeof(short) * n);
	for (i=0;i<n;i++) scanf("%hd",&a[i]);

	qsort(a,n,sizeof(short),compare);
	if (n%2==0) {
		ans = (double)(a[n/2] + a[n/2-1]) / 2.0;
	} else {
		ans = a[n/2];
	}

	printf("%.1f\n",ans);

	return 0;
}