#include<bits/stdc++.h>
using namespace std;
int main(){
  int i,j,n;
  int a[100]={0};
  float b=0;
  cin>>n;
  for(i=0;i<n;i++) cin>>a[i];
  for(i=0;i<n-1;i++){
  	for(j=0;j<n-i-1;j++)
  	  if(a[j]>a[j+1]) swap(a[j],a[j+1]);
		}
  if(n%2==0) b=(a[n/2-1]*1.0+a[n/2])/2;
  else b=a[n/2]*1.0;
  printf("%.1f",b);
  return 0;
}
/**************************************************************
	Problem: 1233
	User: wtq001
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/