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: ['s', 'M', 'U', '5383']

Answer: 5383


Question: ['4515', '3911', 'M', 'T', 'w', 'F']

Answer: 8426


Question: ['3233', 'E', '4563', 'o', 'g', '79', '8023', '4631', 'L', 'h', 'h', '1377']

Answer:
21906