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]: ['57', '9977', '2657', 'p', '9573', '7745', '4755', 'U']
[A]: 34764


[Q]: ['Q', '6383', 'P', '8455', '3881', '5821', 'e', 'v', '1421', 'Q', '6377', '3157', '6407', 'q']
[A]: 41902


[Q]: ['1771', 'K', 'v', '773', '2917', '2243', 'r', 'W']
[A]:
7704