TASK DEFINITION: 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.
PROBLEM: ['2913', 'b', 'j', '7591', 'O', 's', '5589', '4995', '7503', 'U', 'S', 'C', '6797']

SOLUTION: 35388

PROBLEM: ['o', '7099', 'G', 'v', 'H', 'J', 'k', '1607', 'i', '9765', '2489', '8031']

SOLUTION: 28991

PROBLEM: ['P', 'K', '5729', 'K', '1025', 'E', 'I', '259', 'u', '2499', 'k', 'q', '1729']

SOLUTION:
11241