#include<bits/stdc++.h>
using namespace std;

#define rep(i,n) for(int i=0;i<(n);i++)
#define pb push_back
#define all(v) (v).begin(),(v).end()
typedef vector<int>vi;

int main(){
    int n;cin>>n;
    vi a(n);
    rep(i,n)cin>>a[i];
    sort(all(a));

    if(n&1)cout<<a[n/2]<<endl;
    else cout<<(a[n/2]+a[n/2-1])/2.0<<endl;
    return 0;
}