In this task, you are given an input list A. You need to find all the elements of the list that are numbers and calculate their sum.

Ex Input:
['3839', 'D', '4741', 'L']

Ex Output:
8580


Ex Input:
['6731', 'f', '4561', '5601', 'i']

Ex Output:
16893


Ex Input:
['z', 'c', 'F', 'L', 'y', 'L', 's', 'j', '7803', 'Q', '2199']

Ex Output:

10002