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: ['b', '5447', 'R', '8489', 'L', '627', 'P', '7491', 'c', 'c', 'r', '6923', '1167']

A: 30144
****
Q: ['w', 'I', 't', '813', 'K', '5785']

A: 6598
****
Q: ['I', '7815']

A:
7815
****