백준 20115

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;

class Main20115 {

   public static void main(String[] args) throws Exception {
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      int N = Integer.parseInt(br.readLine());
      int[] x = new int[N];

      StringTokenizer st = new StringTokenizer(br.readLine());
      for (int i = 0; i < N; i++) {
         x[i] = Integer.parseInt(st.nextToken());
      }

      Arrays.sort(x);

      double answer = x[N - 1];
      for (int i = N - 2; i >= 0; i--) {
         double result = (double)x[i] / 2;
         answer += result;
      }

      System.out.printf("%.1f", answer);
   }
}