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]: ['4975', 'M', 'C', 'D', 't', 'i', 't', 'L']
[A]: 4975


[Q]: ['57', '9977', '2657', 'p', '9573', '7745', '4755', 'U']
[A]: 34764


[Q]: ['N', 'i', 'w', 'O', 'E', 's', 'X']
[A]:
0