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: ['Y', '9053', 'N', '6921']

A: 15974
****
Q: ['c', '7415', '6253', '4477', 't', '9449', '7733', '2325', 'Z', '5413', 'q', 'm', 'R', '8619', '7289', '857', '7273', '7425']

A: 74528
****
Q: ['9549', 'X', 'C']

A:
9549
****