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: ['r', 'z', 'u', 'D', '3449', 'E', 'f', 'w', '1627', '4093', '955', 'i', 's', 'R', 'b', '9773', '2169', 'M', '9305', '4775']
Example Output: 36146

Example Input: ['3557', '3345', '307', '9791', '1897', 'O']
Example Output: 18897

Example Input: ['1811', 'K', 'F', 'n', 'd', '9539', '9175', '5061', 'H', 'P', '8437', '5819', '2889', 'u', '3875']
Example Output:
46606