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 JavaScript (Node.js 12.16.1) (judge verdict: Accepted)

"use strict";

const main = arg => {
    const input = arg.trim().split("\n");

    const N = BigInt(input[0].split(" ")[0]);
    const K = BigInt(input[0].split(" ")[1]);
    if(N%K == 0){
        console.log(0)
        return
    } 

    let tmp = N % K
    if(Number(tmp) < Math.abs(Number(K-tmp))) console.log(Number(tmp))
    else console.log(Math.abs(Number(K-tmp)))

}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));