#include<stdio.h>
int cmp(const void *a,const void *b){
	return *(int*)a-*(int*)b;
}
int main(){
	int a[1000],n,i;
	scanf("%d",&n);
	for(i=0;i<n;i++) scanf("%d",&a[i]);
	qsort(a,n,sizeof(int),cmp);
	switch(n%2){
		case 1:
		printf("%d\n",a[n/2]);
		break;
		case 0:
		printf("%.1f\n",(a[n/2]+a[n/2-1])/2.0);
	}
	return 0;
}