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.*;
 
public class Main{
    public static  void main(String[]args){
        Scanner sc = new Scanner(System.in);
        long N=0;
        long K=0;
        N=sc.nextLong();
        K=sc.nextLong();
        long m=0;
        m=N%K;
        long min=0;
        min=N-m*K;
        if(min>N-(m-1)*K)
        min=N-(m-1)*K;
        else if(min>N-(m+1)*K)
        min=N-(m+1)*K;
        System.out.println(min);
    }
}