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: ['R', 'C', 'S', 'x', '1529', 'r']

A: 1529
****
Q: ['9787', '1491', '4411', '5261', 'U', '9787', 'b']

A: 30737
****
Q: ['s', '3881', 'l', '5271', '9227', 'Z', '5429', '7691', '6127', '6301', '8533', 'T', '233', 'j', '1685', 'F', 'b', '3797', '6633', '7917']

A:
72725
****