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:
['c', '4501', 'O']

Ex Output:
4501


Ex Input:
['6787', 'W', 'I', '4929', 'j', 'I', '3487', 'F', '3927', 'Q', 's', 'X', '9939', 'n']

Ex Output:
29069


Ex Input:
['C', '7689', 'I', '1295', '9493', '4773', 'l', '3617', '4137', 'O', 'b', 'Z', '5611', '4477', '9955', '479', '5071']

Ex Output:

56597