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: ['2775', '7405', 'F', 'D', '9025', '827', 'e', 'j', 's', 'e', 'Q', '1137', 'G']

Answer: 21169


Question: ['4749', '1169', '4273', 'X']

Answer: 10191


Question: ['D', 'h', 'W', 'B', 'N', '115', 't', 'I', 'E', 'P', 'l', 'K', '6501', '3159', 'K', 'x', 'n', '3621', 'f']

Answer:
13396