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: ['h', '2335', '2669', '6035', '9901', '7721', 's', '6181', 'C', 'l', 'x', '8275', '1103', 'S', '6447']

SOLUTION: 50667

PROBLEM: ['U', '3063', 'q', 'j']

SOLUTION:
3063