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: Wrong Answer)

/* package codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class Main
{
  public static void main (String[] args) throws java.lang.Exception
   {
	try{
	    Scanner sc=new Scanner(System.in);
		  long n=sc.nextLong();
		  long k=sc.nextLong();
      if(n==0)
         System.out.println(k);
      else
      {long m=n%k;
		 if(m==0)
		  System.out.println("0");  
         
		 else if(m==n)
		   System.out.println(m);
		 else if(k-m>0)
		 System.out.println(k-m);
		       
      }   
	   }     
	catch(Exception e)
		 {}
 	}
}