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.

['5573', '6221', 'C', '8649', '6603', 'q', '9403']
36449

['A', 'S', 'c', 'I', 'M', 'P', '8739', '879', '1401', '3941', '4061', 'q', 'P', '2805', '4473']
26299

['7329', 'c', '3789', '2853', '3729', 'D']

17700