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 ProblemC {

    public static void main(String[] args) throws IOException {
        init();
        new ProblemC().run();
        out.flush();
        out.close();
    }

    static void init() throws IOException {
        in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
        out = new PrintWriter(new OutputStreamWriter(System.out));
        in.ordinaryChars(0, 65535);
        in.wordChars(0, 65535);
        in.whitespaceChars(' ', ' ');
        in.whitespaceChars('\n', '\n');
        in.whitespaceChars('\r', '\r');
    }

    // класс для пар
    class Pair<L, R> {
        private final L X;
        private final R Y;

        public Pair(L X, R Y) {
            this.X = X;
            this.Y = Y;
        }

        public L getX() {
            return X;
        }

        public R getY() {
            return Y;
        }

        @Override
        public int hashCode() {
            return X.hashCode() ^ Y.hashCode();
        }

        @Override
        public boolean equals(Object o) {
            if (!(o instanceof Pair)) return false;
            Pair pairo = (Pair) o;
            return X.equals(pairo.getX()) && Y.equals(pairo.getY());
        }
    }

    static final long INFL = 200000000000000000L;
    static final int INF = 2000000000;
    static final boolean DEBUG = true;

    static StreamTokenizer in;
    static PrintWriter out;

    static void print(String s) {
        print(s, 0);
    }

    static void print(String s, int debug) {
        if (debug == 0 || DEBUG) {
            out.print(s);
        }
    }

    static void println(String s) {
        println(s, 0);
    }

    static void println(String s, int debug) {
        if (debug == 0 || DEBUG) {
            out.println(s);
        }
    }

    static void printArray(int[] arr) {
        println(Arrays.toString(arr));
    }

    static void printArray(char[] arr) {
        println(Arrays.toString(arr));
    }

    static void printArray(String[] arr) {
        println(Arrays.toString(arr));
    }

    static void sort(int[] a) {
        Random rnd = new Random();
        for (int i = a.length - 1; i > 0; i--) {
            int index = rnd.nextInt(i);
            a[i] ^= a[index];
            a[index] ^= a[i];
            a[i] ^= a[index];
        }
        Arrays.sort(a);
    }

    static char[] inChars;
    static int inCharsInd;

    static String next() throws IOException {
        in.nextToken();
        return in.sval;
    }

    static char nextChar() throws IOException {
        while (inChars == null || inCharsInd >= inChars.length) {
            inChars = next().toCharArray();
            inCharsInd = 0;
        }
        return inChars[inCharsInd++];
    }

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

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

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

    private void run() throws IOException {
        int T = nextInt();
        for (int i = 0; i < T; i++) {
            solve();
        }
    }

    private void solve() throws IOException {
        long X = nextInt();
        long Y = nextInt();
        long P = nextInt();
        long Q = nextInt();

        if (P == Q){
            if (X == Y) {
                out.println(0);
            } else {
                out.println(-1);
            }
            return;
        }
        if (P == 0){
            if (X == 0){
                out.println(0);
            } else {
                out.println(-1);
            }
            return;
        }
        long counter = 0;
        long k = (long)Math.ceil(X*1.0/P);
        counter += k*P-X;
        Y += k*P-X;

        long k2 = (Y - k*Q > 0)?(long)Math.ceil((Y - k*Q)*1.0/(Q-P)):0;
        counter += k2*P;
        Y += k2*P;
        counter += ((k+k2)*Q - Y);
        out.println(counter);
    }

}