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:
['M', 'F', '4477', '1565', '4407', 'r', 'v', '7237', '83', '5243', 'O', 'z', 'W', '7703', 'Q', 'i', '9657', 'n']

Ex Output:
40372


Ex Input:
['1203', '6179', '9835']

Ex Output:
17217


Ex Input:
['N', 'P', '8179', '7001', 't', '4497', 'u']

Ex Output:

19677