A Bar Chart With a Reference Average Line

A shop manager at Alderwood Supply pins up daily sales as a bar per day, and asks for one dashed line ruled across the whole chart so that a glance says which days beat a typical day and which fell short. The line sits at the mean — every day's figure added together and shared equally between the days — not at the middle-ranked day. The caption under the chart repeats that figure in words, and the caption is what is checked here.

Task: Print the mean daily sales figure.

Input

The first line holds an integer n, the number of days. Each of the next n lines holds one day's sales figure.

Output

One line holding the mean, written with exactly two decimal places.

Example:

Input:
3
100
200
300

Output:
200.00