AT_abc465_d [ABC465D] X to Y
Description
You are given integers $ X,Y $ , and an integer $ K $ that is at least $ 2 $ .
There is a variable $ x $ , which is initially $ x=X $ . You can perform the following operation on $ x $ zero or more times:
- Choose an integer $ y $ satisfying $ \displaystyle \left\lfloor \frac xK \right\rfloor=y $ or $ \displaystyle \left\lfloor \frac yK \right\rfloor=x $ , and replace the value of $ x $ with $ y $ .
Here, $ \displaystyle \left\lfloor z \right\rfloor $ is defined as the greatest integer not exceeding $ z $ , for a real number $ z $ .
Find the minimum number of operations required to make $ x=Y $ . Under the given constraints, it can be proved that there always exists a way to make $ x=Y $ in a finite number of operations.
You are given $ T $ test cases; solve each of them.
Input Format
The input is given from Standard Input in the following format:
> $ T $ $ \text{case}_1 $ $ \text{case}_2 $ $ \vdots $ $ \text{case}_T $
The $ i $ -th $ (1\le i\le T) $ test case $ \text{case}_i $ is given in the following format:
> $ X $ $ Y $ $ K $
Output Format
Output the answers for the test cases in order, separated by newlines.
Explanation/Hint
### Sample Explanation 1
Consider the first test case.
By performing the following operations, $ x=Y $ can be achieved in two operations:
- Choose $ y=3 $ . Since $ \displaystyle\left\lfloor\frac{x}K \right\rfloor=\left\lfloor\frac{11}3 \right\rfloor=3 $ , this choice is valid. Then, replace the value of $ x $ with $ 3 $ .
- Choose $ y=9 $ . Since $ \displaystyle\left\lfloor\frac{y}K \right\rfloor=\left\lfloor\frac{9}3 \right\rfloor=3 $ , this choice is valid. Then, replace the value of $ x $ with $ 9 $ .
$ x=Y $ cannot be achieved in fewer than two operations, so output $ 2 $ on the first line.
### Constraints
- $ 1\le T\le 2\times 10^5 $
- $ 0\le X,Y\le 10^{18} $
- $ 2\le K\le 10^{18} $
- All input values are integers.