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.

['F', 'z', '1159', '345']
1504

['D', 'P', '9951', '2897', 'V', 'C', 'B', 'H', 'c', 'h', '2843', 'a']
15691

['9533', '8165', '1333', 'w', '4921', '9821', '4745', '9139', '4685', '7127', 'u', 'k', '3923']

63392