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:
['D', 'R', 'Y', '4929', 'P', '7929']

Ex Output:
12858


Ex Input:
['k', '1489', 'x', '6543', 'I', 'l', 'D', '6299', '1473', 'a', '7661', 'z', 'E', 'Z', 'U', '3671', '2873', 'e', 'p']

Ex Output:
30009


Ex Input:
['7613', '1427', '3513', 't', 'y']

Ex Output:

12553