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: ['h', '6937', 'U', 'f', 'S', 'm', '9699', 'E', '4559', 'p', 'Z', 'o', '6409', 's', '4537', '5135', '6901', '6489', '5833', 'l']

A: 56499
****
Q: ['4145', 't']

A: 4145
****
Q: ['U', 'r', 'j', 'F', 'o', '7305', '3375']

A:
10680
****