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.

['m', '3481']
3481

['s', '9377', '3663', '1375', 'j', 'L', '7943', '1711', '7409', '9115', '1227', 'I', 'U']
41820

['D', '3225', '4485', '6795', 'D', 'N', 'w', '5019', '6411', '9369', 'q', '445', 'x', '637', 'P', 'L', 'k', 'b', 'c']

36386