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.

['t', 'G', '217', 'W', 'l', 'j', 'd', 'U', '6795', '1609', 'n', '6919', '617', '5753']
21910

['2787', '6085', '6989']
15861

['3975', 'J', '1751', '4027', 'p', '9693', '409', '9487', 'M', '6825', 'f', 'A']

36167