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.

['l', '5369', 'z', 'U', 's', '2357', '3367', 't', '6539', 'K', 'a', 'Q', 'x', 'e', '6459', 'K', 'B', 'f', 'j']
24091

['7755', '8383', 'y', 'k', '4869', '2809']
23816

['4573', '1695', 'd', '6115', '2861', 'S', '5963', '2749', 'C', 'Q', 'r', 't']

23956