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


question:
['1073', 'i', 'o', 'j', 'O', 'g', 'X', '3261', '5105', '4831', 'J']
answer:
14270


question:
['6265', 'U', '9417', 'k', 'K', '43', '7591']
answer:

23316