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.

['D', 'R', 'Y', '4929', 'P', '7929']
12858

['6051', '5303', '1509', '2797', 'Z', '4777', '721', '8563', 'K', '63', '9115', 'd', '7305', '9743', '7409']
63356

['4433', '2983', '7983', 'j', '6345', '8219', '8597', '6797', '2045', 't', '8727', 'o', 'd']

56129