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.

['9863', 'y']
9863

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

['R', '2407', '3283', '3833', 'A', '4593', '9469', 'S', 'k', 'P', 'I', 'r']

23585