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: ['6577', 'Q', '6865', '7671', 'N']
Example Output: 21113

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

Example Input: ['C', '3133', '2183', '5793', '9305', 'd', 'g', '6501']
Example Output:
26915