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]: ['D', '1693', 'f', 'B', 'o', '3947', '8667', 'f', '6721', '4191', '79']
[A]: 25298


[Q]: ['Q', '8841', 'H', 'v', '2435', '8221', '807', 'P', '2247', 'M', '4609', '5657', 'k', '2807', 'j', '8451']
[A]: 44075


[Q]: ['L', '4003']
[A]:
4003