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: ['D', 'R', 'Y', '4929', 'P', '7929']

Answer: 12858


Question: ['1073', 'i', 'o', 'j', 'O', 'g', 'X', '3261', '5105', '4831', 'J']

Answer: 14270


Question: ['1299', '3523', '8163', '9569', '9593', 'n', 'k', '7387', 'B', 'N', '953']

Answer:
40487