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.

['j', 'f', '3831', 'B', 'D']
3831

['3655', '1349', '6519', '1019', 'v', '4811', '8609', '9147', '8225', '2665', '2627', '5839']
54465

['j', 'u', 'n', '7653', 'v', '3121', '8067', '7209', '5793', 'x', '5641', '5579', '9787', 'N', 'q', 'F']

52850