Cirno(チルノ) is an ice elf. Her hobby is tricking on others. But the biggest problem is that - Cirno is too foolish to do tricking. She knows this, so she makes statistics to calculate the probability that she can do tricking successfully.

Cirno writes down some probabilities that she may succeed. And she delete the lowest one, because it's too foolish and she can't believe in it. Then she delete the highest one, because she thinks it's impossible.

After that, she wants to know the average of the left probabilities.

For each case, you should output the average of the left probabilities. Keep two decimal places.

Use 'double' to replace 'float'.