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.

Ex Input:
['291', 'R', 'N', '983', '2879', 'C', '3797', '4837', '793', '5489', 'k', '535', 'L', '3605', 's', '3701', 'U', '4399', '2489', '4739']

Ex Output:
38537


Ex Input:
['3575', '8877', '3231', 'v', '9083', '317', 'M', '8975', 'x', 'F']

Ex Output:
34058


Ex Input:
['1365', 'n', 't', '6353', 'p', 'l', '6403', '6491', 'j', '6511', '8529', '2049', 'o', 'Z', '51', 'p', 'Q', '4751', '5493']

Ex Output:

47996