instruction:
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.
question:
['u', 'B', '2509', 'U', 'R', '7497', '1897', '8697', 't', 'W', '1021', '7937', 'F', 'g', '6901', 'I', '2957']
answer:
39416


question:
['A', 'S', 'c', 'I', 'M', 'P', '8739', '879', '1401', '3941', '4061', 'q', 'P', '2805', '4473']
answer:
26299


question:
['J', '5795', 'k', 'r', 'b', 'l', '8857', 'T', 'P', '6207', '21', '7201', 'a', 'E', 'p', '351', '4545']
answer:

32977