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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>

int main(void)
{
    int x,y;
    int a=0;
    int b=0;
    int ans=0;

    scanf("%d %d",&x,&y);
    // printf("%d %d",x,y);

    if (x-y<0)
        a=(x-y)*-1;
    else
        a=x-y;

    if (a-y<0)
        b=(a-y)*-1;
    else
        b=a-y;

    if (a<=b)
        ans=a;
    else
        ans=b;
    
    if (b==x-y-y && b>0)
        printf("0\n");
    else
        printf("%d\n",ans);
    
    return 0;



}