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: ['X', '989', 'U', '9551', '6385', 'Y', '1433', 'J', '1833', '685', 'u']

Answer: 20876


Question: ['7959', '1345', '4605', '6453', 'Q']

Answer: 20362


Question: ['8515', 'N', '5663', '227', 'k', 'k', '8741', '2403', 'm', '3895', 'a']

Answer:
29444