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 9.2.1) (judge verdict: Wrong Answer)

#include<stdio.h>
int main ()
{
    long long n,k,x,j,y,i;
    scanf("%lld %lld", &n, &k);
    if(k>=n){x=n;}
    else{if(n%k==0){x=0;}
         else{i=k*((n/k)+1);
              j=k*(n/k);
         x=n-i;
         y=n-j;
         if(x<0){x=-x;}
         if(y<0){y=-y;}
         if(y<x){x=y;}
        }}
    printf("%lld\n", x);

}