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: ['6515', '5525', 'o', 'Q', '9049', 'f', 'p', 'X', '2057', 'h', '7585', '3617', '7817']

SOLUTION: 42165

PROBLEM: ['D', 'C', '7295', 'g', 'j', '1387', 'O', '4701', 'B', 'd', 'W', 'b', 's', 'n', 'n', '4917', '2941', '1825', 'x']

SOLUTION: 23066

PROBLEM: ['D', 'z', 'O', 'm', '4539', 'A', '1847', 'u', 'L', 'x', '4169', '1089', '2769', 'r', '9769', '6509']

SOLUTION:
30691