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]: ['s', 'g', 'Z', '8919', 'R']
[A]: 8919


[Q]: ['l', 'B', 'Y', '7543', '5091', '1917']
[A]: 14551


[Q]: ['3903', 'R', 'X', '953', 'M', 'F', '3971']
[A]:
8827