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: ['v', 'a', 'O', 'S', 'r', 'T', 'r', 'K', 'K', '7781', '1749']
Example Output: 9530

Example Input: ['j', 'f', '3831', 'B', 'D']
Example Output: 3831

Example Input: ['1681', '4609', 'a', 'k', '1453', '1063', '2535', '5321', 'Q', 'F', '6123', 'u', '5785', 'A', 'M', '1157', 'p', 'z', 'L']
Example Output:
29727