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.

Example Input: ['F', 'z', '1159', '345']
Example Output: 1504

Example Input: ['k', '1489', 'x', '6543', 'I', 'l', 'D', '6299', '1473', 'a', '7661', 'z', 'E', 'Z', 'U', '3671', '2873', 'e', 'p']
Example Output: 30009

Example Input: ['B', 'q', '8537', '6949', 'o', '4303', 'i', '435', 'x', 'w', 'O', '4235', 'l', '1737', '8899', '7659', 'F', '7055', 'l', '9827']
Example Output:
59636