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.

Q: ['3705', '9217', 'C', '4609']

A: 17531
****
Q: ['B', 's']

A: 0
****
Q: ['7395', '5681', '8099', '1171', '9539', 'C', 'i', 'T', 'E', '6703', '3845', 'I', '4549', '6931', '9697', '8547']

A:
72157
****