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>
#include<math.h>
#include<stdlib.h>

int main()
{

long long int i,n,m,min1=0,min2;

scanf("%lld%lld",&n,&m);

min2=abs(m-n);
if(n<m&&!(m-n<n))
    {
        printf("%lld",n);

    }
else if (n%m==0)
   {
     printf("%d",0);

   }
else{
  while(1){
    min1=abs(m-n);
    n=min1;

    if(min1>min2)
        break;
    min2=min1;



}





    printf("%lld",min2);


}




}