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: ['M', '6989', 'I', 'w', '3591', '3067', '3883', 'C', '6049', '5723', 'j', '5989', 'C', 'R', '475', '7779', '671']
Example Output: 44216

Example Input: ['6787', 'W', 'I', '4929', 'j', 'I', '3487', 'F', '3927', 'Q', 's', 'X', '9939', 'n']
Example Output: 29069

Example Input: ['3379', '8793', '2971', '411', '6569', 'd', '5909', '1291', '8897', '6069', 'y', 'i', 'O', 'i', 'a']
Example Output:
44289