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

['6787', 'W', 'I', '4929', 'j', 'I', '3487', 'F', '3927', 'Q', 's', 'X', '9939', 'n']
29069

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

30144