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 Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.util.*;
class Main
{
  public static void main(String[] args)
  {
    Scanner sc = new Scanner(System.in);
    
    long n = sc.nextLong();
    long k = sc.nextInt();
    
    while(true){
      
     long x = n-k;
      if(x < 0){
        x*=-1;
      }if(x==0){
          System.out.println(0);
          return;
        }
    
      
      if(n>x){
        n=x;
      }else{
        System.out.println(n);
        return;
      }
      
    }
  }
}