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.

['c', '7415', '6253', '4477', 't', '9449', '7733', '2325', 'Z', '5413', 'q', 'm', 'R', '8619', '7289', '857', '7273', '7425']
74528

['7669', '3367', 'A', 'Z', '6173', '4391', 'f', 'S', '9657', '2631']
33888

['L', 'V', '8083', 'h', '6173', '7363', 'v', 'R', '8809', 'L', '7979', 'y', 'W', 'P', 'v', '3505', 'x']

41912