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.

Example Input: ['291', 'R', 'N', '983', '2879', 'C', '3797', '4837', '793', '5489', 'k', '535', 'L', '3605', 's', '3701', 'U', '4399', '2489', '4739']
Example Output: 38537

Example Input: ['E', '9289', 'j', '1847', 'u', 'w', 'z', '4045', '9567', '3133', '2967', 'I', '1927', 'I', 'f', 'T']
Example Output: 32775

Example Input: ['4941', '6339', '6533', 'h', 'k', 'd', '8603']
Example Output:
26416