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.

[Q]: ['P', '237', 'X', '8893', '7931', 'F', '8359', 'S', '6931', '6953', 'r']
[A]: 39304


[Q]: ['Q', '2271', '1803', '2363']
[A]: 6437


[Q]: ['8647', 'T', '545', 'E', '1513', 'X', '9979', '3835', '1771', 'w', '1029', 'j', '3881', 'F', '5827', 'q', '1901']
[A]:
38928