CODE EXAMPLE FOR PYTHON

codeforces problem 200B

# codeforces problem 200B solution in python. hope you've tried enough
n = int(input())
p = list(map(int, input().split()))[:n]
x = 100 / n
percentage = 0
for i in p:
    if i != 0:
        percentage += x / (100 / i)
print('%.12f' %percentage)