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]: ['I', '7815']
[EX A]: 7815

[EX Q]: ['8667', '4129', '7075', '6345', '1315', 'M', 'F', '9073']
[EX A]: 36604

[EX Q]: ['3831', 'A', 'X']
[EX A]:
3831