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: ['M', '6989', 'I', 'w', '3591', '3067', '3883', 'C', '6049', '5723', 'j', '5989', 'C', 'R', '475', '7779', '671']

SOLUTION: 44216

PROBLEM: ['P', '6161', 'k', '5925', 'h', 'G', 'n']

SOLUTION: 12086

PROBLEM: ['5837', 'c', '6095', '4149', 'C', 'I', '6285', 'j', 'x', '7355', '5349', 'l', 'S']

SOLUTION:
35070