instruction:
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.
question:
['R', 'C', 'S', 'x', '1529', 'r']
answer:
1529


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


question:
['7551', '4669', 'C', '9451', '9779', '5337', '3349', 'n', '6713', '3673', '1539', 'w']
answer:

52061