You are an experienced Codeforces user. Today you found out that during your activity on Codeforces you have made y submissions, out of which x have been successful. Thus, your current success rate on Codeforces is equal to x / y.

Your favorite rational number in the [0;1] range is p / q. Now you wonder: what is the smallest number of submissions you have to make if you want your success rate to be p / q?

Input

The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.

Each of the next t lines contains four integers x, y, p and q (0 ≤ x ≤ y ≤ 109; 0 ≤ p ≤ q ≤ 109; y > 0; q > 0).

It is guaranteed that p / q is an irreducible fraction.

Hacks. For hacks, an additional constraint of t ≤ 5 must be met.

Output

For each test case, output a single integer equal to the smallest number of submissions you have to make if you want your success rate to be equal to your favorite rational number, or -1 if this is impossible to achieve.

Example

Input

4
3 10 1 2
7 14 3 8
20 70 2 7
5 6 1 1


Output

4
10
0
-1

Note

In the first example, you have to make 4 successful submissions. Your success rate will be equal to 7 / 14, or 1 / 2.

In the second example, you have to make 2 successful and 8 unsuccessful submissions. Your success rate will be equal to 9 / 24, or 3 / 8.

In the third example, there is no need to make any new submissions. Your success rate is already equal to 20 / 70, or 2 / 7.

In the fourth example, the only unsuccessful submission breaks your hopes of having the success rate equal to 1.
import java.io.*;
import java.util.*;

public class C {

    void solve() {
        long t = in.nextLong();
        for (int i = 0; i < t; i++) {
            long x = in.nextLong();
            long y = in.nextLong();
            long p = in.nextLong();
            long q = in.nextLong();

            if (p == 0) {
                if (x == 0) {
                    out.println(0);
                } else {
                    out.println(-1);
                }
                continue;
            }

            if (p == 1 && q ==1) {
                if (x == y) {
                    out.println(0);
                } else {
                    out.println(-1);
                }
                continue;
            }

            if (x*q == p*y) {
                out.println(0);
                continue;
            }

            long hi = Long.MAX_VALUE / Math.max(p, q);
            long lo = 1;
            while (lo + 1 < hi) {
                long mid = lo + (hi - lo) / 2;
                if (p * mid >= x && q * mid >= y && (p*mid - x <= q*mid - y)) {
                    hi = mid;
                } else {
                    lo = mid;
                }
            }
            long mul = 0;
            if (p * lo >= x && q * lo >= y && (p*lo - x <= q*lo - y)) {
                mul = lo;
            } else if (p * hi >= x && q * hi >= y && (p*hi - x <= q*hi - y)){
                mul = hi;
            }
            out.println(mul == 0 ? -1 : q*mul - y);
        }
    }

    FastScanner in;
    PrintWriter out;

    void run() {
        try {
            in = new FastScanner(new File("C.in"));
            out = new PrintWriter(new File("C.out"));

            solve();

            out.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

    void runIO() {

        in = new FastScanner(System.in);
        out = new PrintWriter(System.out);

        solve();

        out.close();
    }

    class FastScanner {
        BufferedReader br;
        StringTokenizer st;

        public FastScanner(File f) {
            try {
                br = new BufferedReader(new FileReader(f));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }

        public FastScanner(InputStream f) {
            br = new BufferedReader(new InputStreamReader(f));
        }

        String next() {
            while (st == null || !st.hasMoreTokens()) {
                String s = null;
                try {
                    s = br.readLine();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                if (s == null)
                    return null;
                st = new StringTokenizer(s);
            }
            return st.nextToken();
        }

        boolean hasMoreTokens() {
            while (st == null || !st.hasMoreTokens()) {
                String s = null;
                try {
                    s = br.readLine();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                if (s == null)
                    return false;
                st = new StringTokenizer(s);
            }
            return true;
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }
    }

    public static void main(String[] args) {
        new C().runIO();
    }
}