Build a tree

HazelFan wants to build a rooted tree. The tree has $n$ nodes labeled $0$ to $n-1$, and the father of the node labeled $i$ is the node labeled $\lfloor\frac{i-1}{k}\rfloor$. HazelFan wonders the size of every subtree, and you just need to tell him the XOR value of these answers.

The first line contains a positive integer $T(1\leq T\leq5)$, denoting the number of test cases.
For each test case:
A single line contains two positive integers $n,k(1\leq n,k\leq10^{18})$.

For each test case:
A single line contains a nonnegative integer, denoting the answer.

2
5 2
5 3

7
6

2017 Multi-University Training Contest - Team 7