Problem: Little Vasya loves orange juice very much. That's why any food and drink in his kitchen necessarily contains orange juice. There are n drinks in his fridge, the volume fraction of orange juice in the i-th drink equals pi percent.

One day Vasya decided to make himself an orange cocktail. He took equal proportions of each of the n drinks and mixed them. Then he wondered, how much orange juice the cocktail has.

Find the volume fraction of orange juice in the final drink.

Input

The first input line contains a single integer n (1 ≤ n ≤ 100) — the number of orange-containing drinks in Vasya's fridge. The second line contains n integers pi (0 ≤ pi ≤ 100) — the volume fraction of orange juice in the i-th drink, in percent. The numbers are separated by a space.

Output

Print the volume fraction in percent of orange juice in Vasya's cocktail. The answer will be considered correct if the absolute or relative error does not exceed 10  - 4.

Examples

Input

3
50 50 100


Output

66.666666666667


Input

4
0 25 50 75


Output

37.500000000000

Note

Note to the first sample: let's assume that Vasya takes x milliliters of each drink from the fridge. Then the volume of pure juice in the cocktail will equal <image> milliliters. The total cocktail's volume equals 3·x milliliters, so the volume fraction of the juice in the cocktail equals <image>, that is, 66.(6) percent.

Solution (in PYTHON):

Solution:
__author__ = 'Devesh Bajpai'
'''
http://codeforces.com/problemset/problem/200/B
Solution: Important is to accept inputs in float. Add all the percentages as fractions to a total. Divide it with
the number of drinks. Also, take care to have 12 places of decimals in the answer. Use format for it.
'''


def solve(drinks,percentages):
    total_percentage = 0
    for percentage in percentages:

        total_percentage += (percentage/100)

    return "{0:.12f}".format((total_percentage/drinks)*100)



if __name__ == "__main__":

    drinks = float(input())
    percentages = map(float,raw_input().split(" "))

    print solve(drinks,percentages)