First break the given xor number like if the number is 11 then break it into 1 + 2 + 8 let's say we store these numbers into a vector arr.

Now if n is less than no. of set bits in the given xor number . Then we need to merge some numbers and it can be done easily.

In other case let's define variable rem = n — no. of set bits in given xor number .

Now if rem is even then we can make all remaining number 1 .

If rem is odd then we find a even number from the arr and add 1 to it . Now fill all the rem no. with 1 this is gonna work (think why ?).

There may be some corner cases when given xor no. is 1 .(Think how can you handle this ) .

Sorry I am very bad at using CF features .