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.
--------
Question: ['7459', '491', '7823', '6965', 'H', '109', 'R', 't', '3959', '2821', 'R', '2807', 'o', 'v', '1305', 'a', '1411', 'r', '3669']

Answer: 38819


Question: ['K', '9121', 'y', '4233', '1513', 'd', '5609', 'C', 'q', 'p', 'S', '627', 'q', 'I']

Answer: 21103


Question: ['I', '3817', 'P', 'P', 'u', 'f', '2623', '4515', 'Y', 'f', '7465', 'p', 'P']

Answer:
18420