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: ['W', '4453', '5895', 'Z', 'A', '7663', '2749', 'f', 'H', '6917', '1215', 'M', '1775', '5397', 'l', '8197', '5209', '8229', 'U']

SOLUTION: 57699

PROBLEM: ['v', '4119', 'I', '475', 'd', 'L', '909', 'F', 'V', '775', 'k', 'A', '9411', '8383', 'W', '1521', 'z', 'j', '7057', 'I']

SOLUTION: 32650

PROBLEM: ['F', 'E', '339', '1855']

SOLUTION:
2194