In this task you will be given a list of numbers and you need to find the mean (average) of that list. The mean of a list can be found by summing every number in the list then dividing the result by the size of that list. The output should be rounded to 3 decimal places.

Ex Input:
[58.371, 4.131]

Ex Output:
31.251


Ex Input:
[21.531, 221.161, -31.194]

Ex Output:
70.499


Ex Input:
[239.009, 122.609]

Ex Output:

180.809