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.

['2087', '8171', 'c', 'd', 'a', '5621', 'n']
15879

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

['q', '8675', '1713', '3847', 'D', 'W', '6375', 'C', '5947', '4521', '811', '6273', 'm', 'S', '4937']

43099