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 Kotlin (1.0.0) (judge verdict: Wrong Answer)

fun main(args: Array<String>) {
  val input1 = readLine()!!.split(" ").map(String::toLong)
  val n = input1[0]
  val k = input1[1]
  var wrkAbsNum = n
  var absNum = 0L
  var befNum = n
  if (k == 1L) {
    println(1)
    return
  }
  while (absNum < befNum) {
    var num = wrkAbsNum - k
    absNum = Math.abs(num)
    befNum = wrkAbsNum
    wrkAbsNum = absNum
  }
  println(befNum)

}