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.

[EX Q]: ['N', 'O', '2635', '8891']
[EX A]: 11526

[EX Q]: ['X', 'f', 'p', 'R', 'N']
[EX A]: 0

[EX Q]: ['5687', '8537', 'A', 'U', 'p', '7641', 'r', '9969', 'l', '8003', '9763', 'T', 'Y', '6689', 'R']
[EX A]:
56289