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: ['r', '6537', '3001', '7879']

Answer: 17417


Question: ['q', 'I', 'E', 'M', 'T', 'i', '8719', 'r', 'V', '9759', 'I', '1793', 'Q', 'P', '5263', 'I', 'O', '8603', 'y']

Answer: 34137


Question: ['U', 'n', 'z', '9333', '6511', 'Q', 'L', '1503', '8839', 'C', 'E', 'X', '5765', '9267', 'b', 'u', 's']

Answer:
41218