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.

[EX Q]: ['2765', '6767', '7645']
[EX A]: 17177

[EX Q]: ['8821', '7221']
[EX A]: 16042

[EX Q]: ['a', '4165', 'x', '2155']
[EX A]:
6320