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]: ['9403', 'u', '4159', 'w', '3467']
[A]: 17029


[Q]: ['y', 'p', '3553', '2155', 'b', 'R', 'j', 'V', 'U']
[A]: 5708


[Q]: ['k', '3945', 'c', '5765', '1843']
[A]:
11553