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.

['L', 'w', '2783', '6993', 'd', '9173']
18949

['b', '5447', 'R', '8489', 'L', '627', 'P', '7491', 'c', 'c', 'r', '6923', '1167']
30144

['s', 'H', '5513', '6551', 'L', 'H', '4463', '6663', 'N', 'g', '8201', 'U', 'D', '1329', '195', 'S', 'H', 'w', 'k', 'T']

32915