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: ['Q', 'v', 't', '223', 'm', 'l', 'c', 'M', 'b', '2227', 'P', 'e', 'n', 'f', 'S', '2205', '3517', '5545']

SOLUTION: 13717

PROBLEM: ['F', 'z', '1159', '345']

SOLUTION: 1504

PROBLEM: ['u', 'B', 'u', '4449', '9907', 'z', 'Z', 'Q', '4205', '7545', '7385', 's', '7477', 'T', '9137', 'O', 'u']

SOLUTION:
50105