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.

['8591', 'J', 'l', 'l', '7023', 'N', 'n']
15614

['A', '9979', '8723', '1131', 'i', 'p', 'M']
19833

['3701', 'v', 'G', 'k']

3701