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: ['f', 'H', 'U', 'l', 'n', 'q', '2701', '339', 'X', 'H', 'O', 'q', '2313']

SOLUTION: 5353

PROBLEM: ['9445', '7291', 'r', 'g', '1175', '7823', '5507', 'j', '7249', '6335', '3853', 'b', 'u', 'S', '365', 'Z', '7489', 'S', 'W', 'e']

SOLUTION: 56532

PROBLEM: ['X', '7281', 'R', '8635', '3765', 'Y', '9213', '4011', 'F', 'D', 'E', '2327', 'F', '5441', '5797', '1503', 'r', '2841', '6863']

SOLUTION:
57677