Neko loves divisors. During the latest number theory lesson, he got an interesting exercise from his math teacher.

Neko has two integers a and b. His goal is to find a non-negative integer k such that the least common multiple of a+k and b+k is the smallest possible. If there are multiple optimal integers k, he needs to choose the smallest one.

Given his mathematical talent, Neko had no trouble getting Wrong Answer on this problem. Can you help him solve it?

Input

The only line contains two integers a and b (1 ≤ a, b ≤ 10^9).

Output

Print the smallest non-negative integer k (k ≥ 0) such that the lowest common multiple of a+k and b+k is the smallest possible.

If there are many possible integers k giving the same value of the least common multiple, print the smallest one.

Examples

Input


6 10


Output


2

Input


21 31


Output


9

Input


5 10


Output


0

Note

In the first test, one should choose k = 2, as the least common multiple of 6 + 2 and 10 + 2 is 24, which is the smallest least common multiple possible.
import java.io.*;
import java.util.*;

public class Task {

    public static void main(String[] args) throws IOException {

        new Task().go();
    }

    PrintWriter out;
    Reader in;
    BufferedReader br;

    Task() throws IOException {

        try {

            //br = new BufferedReader( new FileReader("input.txt") );
            in = new Reader("input.txt");
            out = new PrintWriter( new BufferedWriter(new FileWriter("output.txt")) );
        }
        catch (Exception e) {

            //br = new BufferedReader( new InputStreamReader( System.in ) );
            in = new Reader();
            out = new PrintWriter( new BufferedWriter(new OutputStreamWriter(System.out)) );
        }
    }

    void go() throws IOException {

        int t = 1;
        while (t > 0) {
            solve();
            //out.println();
            t--;
        }

        out.flush();
        out.close();
    }

    int inf = 2000000000;
    int mod = 1000000007;
    double eps = 0.000000001;

    int n;
    int m;
    ArrayList<Integer>[] g;
    void solve() throws IOException {
        long a = in.nextInt();
        long b = in.nextInt();
        if (a < b) {
            a ^= b;
            b ^= a;
            a ^= b;
        }

        long k = 0;
        long max = lcm(a, b);
        long diff = a - b;
        for (int i = 1; i <= Math.sqrt(diff); i++)
            if (diff % i == 0) {
                long k1 = i - a % i;
                long k2 = i - b % i;
                if (k1 == i) k1 = 0;
                if (k2 == i) k2 = 0;
                if (k1 == k2 && lcm(a + k1, b + k2) < max) {
                    max = lcm(a + k1, b + k2);
                    k = k1;
                }
                long x = diff / i;
                if (x != i) {
                    k1 = x - a % x;
                    k2 = x - b % x;
                    if (k1 == x) k1 = 0;
                    if (k2 == x) k2 = 0;
                    if (k1 == k2 && lcm(a + k1, b + k2) < max) {
                        max = lcm(a + k1, b + k2);
                        k = k1;
                    }
                }
            }
        out.print(k);
    }

    long lcm(long a, long b) {
        return a * b / gcd(a, b);
    }

    long gcd(long a, long b) {
        if (b == 0)
            return a;
        return gcd(b, a % b);
    }

    class Pair implements Comparable<Pair> {
        int a;
        int b;

        Pair(int a, int b) {
            this.a = a;
            this.b = b;
        }

        public int compareTo(Pair p) {
            if (a != p.a)
                return Integer.compare(a, p.a);
            else
                return Integer.compare(b, p.b);
        }
    }

    class Item {

        int a;
        int b;
        int c;

        Item(int a, int b, int c) {
            this.a = a;
            this.b = b;
            this.c = c;
        }

    }

    class Reader {

        BufferedReader  br;
        StringTokenizer tok;

        Reader(String file) throws IOException {
            br = new BufferedReader( new FileReader(file) );
        }

        Reader() throws IOException {
            br = new BufferedReader( new InputStreamReader(System.in) );
        }

        String next() throws IOException {

            while (tok == null || !tok.hasMoreElements())
                tok = new StringTokenizer(br.readLine());
            return tok.nextToken();
        }

        int nextInt() throws NumberFormatException, IOException {
            return Integer.valueOf(next());
        }

        long nextLong() throws NumberFormatException, IOException {
            return Long.valueOf(next());
        }

        double nextDouble() throws NumberFormatException, IOException {
            return Double.valueOf(next());
        }


        String nextLine() throws IOException {
            return br.readLine();
        }

        int[] nextIntArray(int n) throws IOException {
            int[] a = new int[n];
            for (int i = 0; i < n; i++)
                a[i] = nextInt();
            return a;
        }

        ArrayList<Integer>[] nextGraph(int n, int m) throws IOException {
            ArrayList<Integer>[] g = new ArrayList[n];
            for (int i = 0; i < n; i++)
                g[i] = new ArrayList<>();
            for (int i = 0; i < m; i++) {
                int x = nextInt() - 1;
                int y = nextInt() - 1;
                g[x].add(y);
                g[y].add(x);
            }

            return g;
        }

    }

}