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: ['4701', 'b', 'i', 'B', 'z', '7837', 'W']

SOLUTION: 12538

PROBLEM: ['9905', 'm', 'Q', 'S', 'T', '7821', '1773', '9515', '3963', '2931', '7023', '8677', '1739', 'O', '909', '9153', '8319', 'k', '2851']

SOLUTION: 74579

PROBLEM: ['3981', '8959', 'b', 't', 't', 'q', '1691', '1741', 'g', '2887', 'h', 's', 'f', 'p', '9263', 'd', 'D', '2129', 'D']

SOLUTION:
30651