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: ['4949', '2459', 'n', 'f', 'n', 'v', '8421', '1519', '4859', 'c', '9923', '2829', 'K', '4937', 'W', 'R']

A: 39896
****
Q: ['Q', '1669']

A: 1669
****
Q: ['3831', '9621', '9767', '5591', 'o', 'k', '5889']

A:
34699
****