Takahashi, who lives on the number line, is now at coordinate X. He will make exactly K moves of distance D in the positive or negative direction.

More specifically, in one move, he can go from coordinate x to x + D or x - D.

He wants to make K moves so that the absolute value of the coordinate of the destination will be the smallest possible.

Find the minimum possible absolute value of the coordinate of the destination.

Constraints

* -10^{15} \leq X \leq 10^{15}
* 1 \leq K \leq 10^{15}
* 1 \leq D \leq 10^{15}
* All values in input are integers.

Input

Input is given from Standard Input in the following format:


X K D


Output

Print the minimum possible absolute value of the coordinate of the destination.

Examples

Input

6 2 4


Output

2


Input

7 4 3


Output

1


Input

10 1 2


Output

8


Input

1000000000000000 1000000000000000 1000000000000000


Output

1000000000000000
//package src.com.jetman.atcoder;

import java.util.Arrays;
import java.util.Scanner;

/**
 * @description:
 * @author: Jetman
 * @create: 2020-08-29 14:39
 **/
public class Main {

    Scanner sc = new Scanner(System.in);

    private void slove() {
        long s = Math.abs(sc.nextLong());
        long k = sc.nextLong();
        long d = sc.nextLong();
        long ans = 0;
        if (s/d > k) {
            ans = s - (k*d);
        } else {
            if (s%d == 0) {
                ans = (k-(s/d))%2==0 ? 0 : d;
            } else {
                ans = (k-(s/d))%2==0 ? s%d : d-(s%d);
                ans = Math.min(ans,(k-(s/d)-1)%2==0 ? d-(s%d) : Long.MAX_VALUE);
            }
        }

        System.out.println(ans);
    }

    public static void main(String[] args) {
        new Main().slove();
    }
}
