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.

['4949', '2459', 'n', 'f', 'n', 'v', '8421', '1519', '4859', 'c', '9923', '2829', 'K', '4937', 'W', 'R']
39896

['f', 'N', '8597', 't', 'K', '9755', 'j', '9747', '7259', '5493', 'n', '7269', '8493', '2279', '5369', 'f']
64261

['y', '1477', '3461', 'N', 'M', '4535', 'R', '2433', 'p']

11906