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]: ['Q', '9787', '7533', '9489', 'C', '1753', '5121', '1405', '9267', '4815', 's', '5887']
[EX A]: 55057

[EX Q]: ['m', '3481']
[EX A]: 3481

[EX Q]: ['f', 'y', '1933', '887', '6759', '8313', '6375', '2767', 'B', 'f', '4215']
[EX A]:
31249