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.
--------
Question: ['Y', 'X']

Answer: 0


Question: ['s', '425', '6135']

Answer: 6560


Question: ['7695', 'T', '5827', '5923', 'k', '1279', 't', '9051', 'u', 'Y', '931', 'k', 'R', '1187', 'P', 'w']

Answer:
31893