Setting Everything at Once With set_theme

A new Marlow & Finch project starts from a single call that fixes the background, the colour set and the element sizes all at once, instead of three separate lines that someone always forgets to keep in step. The first figure is a distribution of readings, and it is captioned with the average of those readings.

Task: Print the mean of the values.

Input

The first line holds one integer n, the number of values, where 1 <= n <= 1000. Then come n lines, one value each. Values may be negative.

Output

One line holding the arithmetic mean of the values -- their total shared out equally -- rounded to 2 decimal places. The mean, not the middle value.

Example:

Input:
4
10
20
30
40

Output:
25.00