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.
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Question: ['135', 'a', 'X', '8067', '8447', '4009', '4221', 'o', 'A', 'x']

Answer: 24879


Question: ['6585', '5263', '9497', '1117', 'a', 'F', 'w', '6595', '547']

Answer: 29604


Question: ['3913', '1139', '9197']

Answer:
14249