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: ['K', '479', 'u', '3489', 'o', '9589', '7153', '7649', '123', 'a', 'A', '3951', '847', 'N', 'R', '947', '9243', 'G', 'a']

A: 43470
****
Q: ['2087', '8171', 'c', 'd', 'a', '5621', 'n']

A: 15879
****
Q: ['2787', 'z', '9351', '3339']

A:
15477
****