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: ['Y', 'X', 'd', 'N', '1877', '2865', 'M', '1249', '9385', 'v', 'o', 'P', 'P', '6029']

SOLUTION: 21405

PROBLEM: ['3351', '6445', 'Y', '8455', 'V', 'z', 'a', 'V', 'S', '8551', '4101', 'q', '8743', '5999', '7155', '3825', '2241', '9957']

SOLUTION: 68823

PROBLEM: ['6917', 'R', 'P', '2293', '3767', 'g', '5483', '963', 'B', '6269', '8111', 'z', 'Z', '9553']

SOLUTION:
43356