#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int m = 1001;
  double sum = 0;
  for (int i = 0; i < (n); i++) {
    int a;
    cin >> a;
    m = min(a, m);
    sum += a;
  }
  sum -= m;
  sum /= 2;
  printf("%.5f", sum);
}
