Split and ADD

You are given three integers $N, L, $ and $R$. It is known that $N$ is a power of $2$, i.e, $N = 2^x$ for some $1 \leq x \leq 60$. You also have a function $f$ that operates on an array $A$ as follows: - If $A$ has length $1$, then $f(A) = A$, i.e, $A$ doesn't change. - Otherwise, let $H_1 = [A_1, A_3, A_5, \ldots, A_{N-1}]$ and $H_2 = [A_2, A_4, A_6, \ldots, A_N]$, i.e, the elements at the odd a