#include <stdio.h> #include <algorithm> using namespace std; //namaega184 int main(){ int n;scanf("%d",&n);int a[1001];for(int i=0;i<n;i++)scanf("%d",&a[i]); sort(a,a+n); double ans; if(n%2)ans=a[n/2]; else ans=(a[n/2-1]+a[n/2])/2.0; printf("%f\n",ans); return 0; }