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]: ['c', 'd']
[EX A]: 0

[EX Q]: ['R', 'J', 'z', 'o', '1121', '7247', '8987', 'u']
[EX A]: 17355

[EX Q]: ['t', 'D', '4401', 'J']
[EX A]:
4401