import java.io.*; import java.util.*; class Main275 { public static void out (Object out) { System.out.println(out); } public static void main (String[] args) throws IOException { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); int n = Integer.parseInt(br.readLine()); int[] nums = new int[n]; String[] str = br.readLine().split(" "); for (int i = 0; i < n; i++) nums[i] = Integer.parseInt(str[i]); Arrays.sort(nums); if (n % 2 == 0) out((nums[n / 2] + nums[n / 2 - 1]) / 2.0); else out(nums[n / 2]); } }