Bitty Permutations

One day the chef went to a magic cave where he got a magical number $M$ , then he was given an array $A$ with $M$ elements and his task is to find two permutations $P1$ and $P2$ such that it contains integers from $0$ to $M-1$. Condition of valid permutations is for every $i$ (1<=$i$<=M), $A[i]$ should be equal to $P1[i]⊕P2[i]$ ,Where $⊕$ denotes bitwise XOR. All elements of $A[i]$ are in suc