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', '7469', 'Y', 'N', '8137']
[EX A]: 15606

[EX Q]: ['3873', 'D', 'J', '2799', 'k', 'F', 'I', '3457', '5647', '4815', '7509', 'Y', '1251', '2211']
[EX A]: 31562

[EX Q]: ['S', 'J', '9379', 'P', '6413', 'M', '9625', 'k', '1411', '655', 'N', '37', 'n', 'k', 'i']
[EX A]:
27520