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: ['6941', 'I', 'j', '6135', '6525', '7853', '5607']

Answer: 33061


Question: ['5331', 'f', '2865', '6019', 'U', 'm', 'g', 'n', 'Y', 'A']

Answer: 14215


Question: ['309', '3347', '8339', 'M', 'L', '3477', '2087']

Answer:
17559