#include <bits/stdc++.h>
using namespace std;
 
int main(){
  int N; cin>>N;
  vector<int> date(N);
  for(int i=0;i<N;i++){
      cin>>date[i];
  }
  sort(date.begin(),date.end());
  if(N%2==1){
      cout<<date[N/2]<<endl;  
  }
  else{
      cout<<(double)(date[N/2-1]+date[N/2])/2<<endl;
  }
}