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.

[Q]: ['R', 'I', 'f', 'K', 'p', '8579', 'e', '1223', 'I', 'K', '8311', '2147', '4241', 'z', '6671', 'r']
[A]: 31172


[Q]: ['U', '5885', 'u', 'Y', 's', 'w', 'j', '9629', '9505', 'U']
[A]: 25019


[Q]: ['7459', '491', '7823', '6965', 'H', '109', 'R', 't', '3959', '2821', 'R', '2807', 'o', 'v', '1305', 'a', '1411', 'r', '3669']
[A]:
38819