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.

Example Input: ['6051', '5303', '1509', '2797', 'Z', '4777', '721', '8563', 'K', '63', '9115', 'd', '7305', '9743', '7409']
Example Output: 63356

Example Input: ['291', 'R', 'N', '983', '2879', 'C', '3797', '4837', '793', '5489', 'k', '535', 'L', '3605', 's', '3701', 'U', '4399', '2489', '4739']
Example Output: 38537

Example Input: ['1113', 's', '8045', 'a', 'H', '6033', 'c', 's', 'n', 'u', 'y']
Example Output:
15191