Maximum Array Xor

Value of an array $A$ of length $L$ is defined as the sum of $(A_i \oplus i)$ for all $0 \leq i \lt L$, where $\oplus$ denotes [bitwise xor operation](https://en.wikipedia.org/wiki/Bitwise_operation#XOR). **Note** that array indices start from zero. You are given an integer $N$ and an array $A$ consisting of $2^N$ integers where $A_i = i$ for all $0 \leq i \lt 2^N$. **Example :** - For $N = 1$