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]: ['291', 'R', 'N', '983', '2879', 'C', '3797', '4837', '793', '5489', 'k', '535', 'L', '3605', 's', '3701', 'U', '4399', '2489', '4739']
[A]: 38537

[Q]: ['L', 'w', '2783', '6993', 'd', '9173']
[A]: 18949

[Q]: ['S', '3699', 'C', 'b', '3101', 'h', '2309', '8893', 'c', 'D', 'J', '2999', '5733', 'k']
[A]:
26734