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: ['6161', 'p', '2839', 'c', '5905', '1729', 'j', '5901', '3013', 'e']

Answer: 25548


Question: ['3873', 'D', 'J', '2799', 'k', 'F', 'I', '3457', '5647', '4815', '7509', 'Y', '1251', '2211']

Answer: 31562


Question: ['I', '559']

Answer:
559