Background

Subtask 0 uses unofficial testdata, and Subtask 1 uses official testdata.

Problem Description

Xiaokeke has two positive integers $a, b$.

One operation is defined as: choose one of $a$ and $b$, and change it by $+1$ or $-1$. Note that you must always ensure $a \ge 1$ and $b \ge 1$.

Now Xiaokeke wants to make $a$ a multiple of $b$ using some number of operations. Please tell him the minimum number of operations needed.

Input Format

One line with two positive integers $a, b$.

Output Format

One line with one number, representing the minimum number of operations needed to make $a$ a multiple of $b$.

9 6

2

Hint

Sample Explanation

You can do $a \leftarrow a + 1$ and $b \leftarrow b - 1$. Then $a = 10$ and $b = 5$, which satisfies the condition. The number of operations is $2$. It can be proven that no smaller number of operations exists.

Other Sample Notes

• Samples 2 to 6: See adjust/adjust*.in and adjust/adjust*.ans in the contestant directory.

Constraints

For all data, it is guaranteed that:

• $1 \le a \le 10^{18}$,
• $1 \le b \le 10^6$,
• $a, b$ are both positive integers.

Translated by ChatGPT 5