Average Midterm Score

You are the teaching assistant for Data Science 101 at Whetcode College, and the midterm is finally graded. Before the course lead runs the review meeting she wants one line for the report: a single number standing in for how the whole cohort did, so this year can be set against last year's.

The cohort is a different size every term and she reruns the same line each time, so the figure has to come out of the code rather than off a calculator.

Task: Print the mean of the cohort's marks as one number, rounded to 2 decimals. Round once, at the end - not mark by mark.

Input

One line holding the whole cohort's marks, separated by single spaces. Every mark is a whole number from 0 to 100, and there is at least one of them.

Output

One line holding the mean, rounded to 2 decimals and printed the way Python prints a float - 80.38, and 69.6 rather than 69.60.

Example:

Input:
72 85 90 65 78 88 95 70

Output:
80.38