PROGRAMMING:Find out the singer's score

Enter a positive integer n (n > 4), and then enter n real numbers to get the singer's score (keep 2 decimal places). There are n (n > 4) judges scoring singers in a singing awards evening. Scoring rules: each judge scores in turn, then removes 2 highest and 2 lowest scores, and calculates the average of the remaining scores as the singer's score
###Input format:
Enter n in the first line
Enter N fractions in the second line
###Output format:
Output the average score on one line
###Input example:
Here is a set of inputs. For example:
```in
ten
10 10 9 9 9 8 8 8 7 7
```
###Output example:
The corresponding output is given here. For example:
```out
aver=8.50
```







answer：If there is no answer, please comment