#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,i,j;
	float z;
	cin>>n;
	int a[n];
	for(i=0;i<n;i++){
		cin>>a[i];
	}
	for(i=1;i<=n-1;i++){
		for(j=0;j<n-i;j++){
			if(a[j]>a[j+1]){
				swap(a[j],a[j+1]);
			}
		}
	}
	if(n%2==0){
		z=(a[n/2]+a[n/2-1])/2.0;
	}else{
		z=a[n/2];
	}
	
	


	/*for(i=0;i<n;i++){
		cout<<a[i]<<" ";
	}*/
	printf("%.1f",z);
	return 0;
}

/**************************************************************
	Problem: 1233
	User: tangkaixuan
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2072 kb
****************************************************************/