Find the "Recursive Size" of a List Inspired by Find the “unwrapped size” of a list.

Define the Recursive Size, RS, of a list containing no lists as its length (number of items contained) and the Recursive Size of a list containing any lists as the sum of its length and the Recursive Size of those lists.

Challenge

Write a program or function that outputs the Recursive Size of any given list in as few bytes as possible.

The input is a list and may contain numbers, strings (if your language has them), and similar lists.



For example:

RS([]) = 0

RS([[]]) = 1

RS([4, 5, 6]) = 3
RS(["four", "five", "six"]) = 3
RS(["[[[[]]]]", "[][][][][]", "][][[[]]][]["]) = 3

RS([[4, 5, 6]]) = 4
RS([["four", "five", "six"]]) = 4
RS([["[[[[]]]]", "[][][][][]", "][][[[]]][]["]]) = 4

RS([[4], [5], [6]]) = 6
RS([["four"], ["five"], ["six"]]) = 6
RS([["[[[[]]]]"], ["[][][][][]"], ["][][[[]]][]["]]) = 6

RS([[[[[[[[[]]]]]]]]]) = 8

RS([[],[],[],[],[],[],[],[]]) = 8

RS([[],[],[[]],[[[[]]]]]) = 8

RS([0,[-1],[2.3,-4.3],[5,[6]],[7,[8,9,[10,11,[12,13,14]]]]]) = 22


Note that if your language has no strings but does have lists of characters, the examples containing "strings" above could actually be lists of characters and have larger results. As an example:

RS([['f','o','u','r'], ['f','i','v','e'], ['s','i','x']]) = 14


This is code-golf, so the shortest answer in bytes wins; no funny-business, as always.

A non-list input may produce any output.
I/O is as flexible as usual.
Python, 42 bytes



f=lambda x:x*0==[]and len(x)+sum(map(f,x))


For a non-list, output 0. For a list, output its length plus the sum of the recursive outputs for its elements.

Lists fall above numbers and below strings in the Python 2 ordering, requiring []&lt;=x&lt;''. Instead, we check x*0==[], whereas the result of 0 for a number or '' for a string.