Problem:
Score : 300 points

Problem Statement

Given any integer x, Aoki can do the operation below.

Operation: Replace x with the absolute difference of x and K.

You are given the initial value of an integer N. Find the minimum possible value taken by N after Aoki does the operation zero or more times.

Constraints

0 ≤ N ≤ 10^{18}

1 ≤ K ≤ 10^{18}

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N K

Output

Print the minimum possible value taken by N after Aoki does the operation zero or more times.

Sample Input 1

7 4

Sample Output 1

1

Initially, N=7.

After one operation, N becomes |7-4| = 3.

After two operations, N becomes |3-4| = 1, which is the minimum value taken by N.

Sample Input 2

2 6

Sample Output 2

2

N=2 after zero operations is the minimum.

Sample Input 3

1000000000000000000 1

Sample Output 3

0

Solution in Scala (2.13.1) (judge verdict: Runtime Error)

import scala.io.Source

object Main extends App {
  val inputStrings = Source.stdin.getLines().toList
  val arr = inputStrings.head.split(' ').take(2).map(_.toInt)
  val result = arr match {
    case Array(n, k) if n == 0 | k == 1 => 0
    case Array(n, k) =>
      val abs = (n - k).abs
      mod(abs, k)
  }
  
  print(result)
  
  def mod(a: Int, b: Int): Int = {
    if (a >= b)
      a % b
    else
      b % a
  }
}