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]: ['t', 'G', '217', 'W', 'l', 'j', 'd', 'U', '6795', '1609', 'n', '6919', '617', '5753']
[EX A]: 21910

[EX Q]: ['S', 'D', '3101', '4967', '8197', '5025', '4257', 'S', 'X', '7641', 'n', '6775', '4719', 'o', '2821', 'x', '5605', '2181']
[EX A]: 55289

[EX Q]: ['9323', 'L', 'S', '5231', 'm', 'o', '1767', 'q', 'M', 'c', '7331', 'r', '1443', '3015', '3427']
[EX A]:
31537