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: ['d', '4553']
Example Output: 4553

Example Input: ['6055', 'v', '9455', 'A', '6817', 'D', '9339', 't', 'K', '1993']
Example Output: 33659

Example Input: ['U', 'J', '4285', 'H', 'l', 'a', 'W', '8663', 'V', 'r', 'F', 'S', '8003', 'j']
Example Output:
20951