XOR of multiples of a number

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1

The brute-force algorithm is getting TLE. I am unable to find anything else to proceed.
Can anyone help me with a better approach?

2

It says “You are not allowed to view the contest” for me.

3

Note m can occupy only 30 bits max.
Let a be m
Let b be 2^30 +m.

We can see that a occupies first 30 bits, and b occupies last 30 bits of the available 60 bits.

Now c will be a xor b, so that a xor b xor c=0

You can see that a, b, c will be divisible by m

4

For you and everyone else who reads this, here’s the contest invite:

5

I think you mean 2^30 * m instead of +.

Also, nice solution.