Snuke has a calculator. It has a display and two buttons.

Initially, the display shows an integer x. Snuke wants to change this value into another integer y, by pressing the following two buttons some number of times in arbitrary order:

* Button A: When pressed, the value on the display is incremented by 1.
* Button B: When pressed, the sign of the value on the display is reversed.



Find the minimum number of times Snuke needs to press the buttons to achieve his objective. It can be shown that the objective is always achievable regardless of the values of the integers x and y.

Constraints

* x and y are integers.
* |x|, |y| ≤ 10^9
* x and y are different.

Input

The input is given from Standard Input in the following format:


x y


Output

Print the minimum number of times Snuke needs to press the buttons to achieve his objective.

Examples

Input

10 20


Output

10


Input

10 -10


Output

1


Input

-10 -20


Output

12
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;

public class Main {
	final int _intMax = Integer.MAX_VALUE; // =2147483647>10^9
	final int _intMin = Integer.MIN_VALUE;
	final long _longMax = Long.MAX_VALUE; // =9223372036854775807L>10^18
	final long _longMin = Long.MIN_VALUE;

	void solve() {
		int[] ia = readNums();
		int x = ia[0];
		int y = ia[1];
		int ans = _intMax;
		if (x <= y)
			ans = min(ans, y - x);
		if (-x <= y)
			ans = min(ans, y - (-x) + 1);
		if (x <= -y)
			ans = min(ans, (-y) - x + 1);
		if (-x <= -y)
			ans = min(ans, (-y) - (-x) + 2);
		pln(ans);
	}

	// -----------------------------------------------------
	// 2018/04/28 r9
	// -----------------------------------------------------
	int abs(int a) {
		return (a >= 0) ? a : -a;
	}

	long abs(long a) {
		return (a >= 0) ? a : -a;
	}

	int max(int a, int b) {
		return (a > b) ? a : b;
	}

	long max(long a, long b) {
		return (a > b) ? a : b;
	}

	int min(int a, int b) {
		return (a < b) ? a : b;
	}

	long min(long a, long b) {
		return (a < b) ? a : b;
	}

	int reed(long a, int n) {
		while (n-- > 0)
			a /= 10;
		return (int) (a % 10);
	}

	int sqrt(long a) {
		return (int) Math.sqrt(a);
	}

	int pint(String s) {
		return Integer.parseInt(s);
	}

	long plong(String s) {
		return Long.parseLong(s);
	}

	String readLine() {
		try {
			return _in.readLine();
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	int readNum() {
		String line = readLine();
		return pint(line);
	}

	long readLong() {
		String line = readLine();
		return plong(line);
	}

	String[] readFlds() {
		String line = readLine();
		return line.split(" ");
	}

	int[] readNums() {
		String[] flds = readFlds();
		int[] nums = new int[flds.length];
		for (int i = 0; i < flds.length; i++)
			nums[i] = pint(flds[i]);
		return nums;
	}

	int[] readNums(int n) {
		int[] nums = new int[n];
		for (int i = 0; i < n; i++)
			nums[i] = readNum();
		return nums;
	}

	long[] readLongs() {
		String[] flds = readFlds();
		long[] nums = new long[flds.length];
		for (int i = 0; i < flds.length; i++)
			nums[i] = plong(flds[i]);
		return nums;
	}

	long[] readLongs(int n) {
		long[] nums = new long[n];
		for (int i = 0; i < n; i++)
			nums[i] = readLong();
		return nums;
	}

	Main pln() {
		_out.println();
		return this;
	}

	Main p(char c) {
		_out.print(c);
		return this;
	}

	Main p(char c, int n) {
		for (int i = 0; i < n; i++)
			p(c);
		return this;
	}

	Main pln(char c) {
		_out.println(c);
		return this;
	}

	Main p(double d) {
		_out.print(d);
		return this;
	}

	Main pln(double d) {
		_out.println(d);
		return this;
	}

	Main p(long l) {
		_out.print(l);
		return this;
	}

	Main pln(long l) {
		_out.println(l);
		return this;
	}

	Main p(String s) {
		_out.print(s);
		return this;
	}

	Main p(String s, int idx) {
		_out.print(s.charAt(idx));
		return this;
	}

	Main pln(String s) {
		_out.println(s);
		return this;
	}

	Main pln(int[] ia) {
		for (int i = 0; i < ia.length; i++)
			_out.println(ia[i]);
		return this;
	}

	Main pln(long[] la) {
		for (int i = 0; i < la.length; i++)
			_out.println(la[i]);
		return this;
	}

	static BufferedReader _in;
	static PrintWriter _out;
	static boolean _bElapsed = false;

	public static void main(String[] args) {
		long start = System.currentTimeMillis();
		_in = new BufferedReader(new InputStreamReader(System.in));
		_out = new PrintWriter(System.out);
		new Main().solve();
		_out.flush();
		long end = System.currentTimeMillis();
		if (_bElapsed)
			System.err.println((end - start) + "ms");
	}
}
