Nested List Summation

Problem Description

Given a nested list (or array) of integers, implement a recursive function that calculates the sum of all the integers. The list can contain integers as well as other nested lists of integers.

For example:

• Input: [1, [2, 3], [4, [5]]]
• Output: 15

Notes:

• You must use recursion in your solution. Avoid using built-in flatten or iterative approaches to fully solve the problem.
• As today is March 20, the Spring Equinox, think of your recursive solution as a fresh start, breaking down the problem step by step like the arrival of spring.

Happy coding and enjoy the new beginnings of spring!