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)

import java.util.Scanner;
import java.lang.Math;

public class Main
{
    public static void main(String[] args)
    {
        Scanner key = new Scanner(System.in);
        long n = key.nextLong();
        long k = key.nextLong();
        if(n<k)
            System.out.println(n);
        else
        {
            while(n>0)
            {
                if(n % k == 0)
                {
                    n = 0;
                    break;
                }
                if(n<k)
                {
                    n = n - k;
                    n = Math.abs(n);
                    break;
                }
                else
                    n = n -k;
            }
            System.out.println(n);
        }
        
    }
}