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: ['2775', '7405', 'F', 'D', '9025', '827', 'e', 'j', 's', 'e', 'Q', '1137', 'G']

SOLUTION: 21169

PROBLEM: ['r', '3537', 'T', '3611', 'k', '4983', 'h', '4317', '8727', 'E', '6471', '8465', 'f', '5429', 'T', '2169', '2171', 'P', '6941', 'D']

SOLUTION: 56821

PROBLEM: ['1313', '2463', '939', 'Z', 'd', 'J', '9625', '9689', 'r']

SOLUTION:
24029