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.

['2683', '4431']
7114

['g', 'h', '9141', '7825', 'a', 'u', '2389', 'r', '9739', '8337', 'Z', 'Z', '6717']
44148

['M', 'h', '1369', 'x', 'R']

1369