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.util.*;
import java.io.*;
 

public class C {
    
    public static void solve() {

        Kattio in = new Kattio(System.in);
       
        int T = in.nextInt();
        while(T-->0) {
            long x = in.nextLong();
            long y = in.nextLong();

            long p = in.nextLong();
            long q = in.nextLong();

            if(p == q && x == y) in.println(0);
            else if(p == q && x != y) in.println(-1);
            else {

                long hi = 3l * 1000000000l;
                long lo = 0;
                long ans = -1; 
                long mid = 0;

                while( lo <= hi) {
                    mid = (lo + hi) / 2;

                    if(q * mid >= y && p * mid >= x && (q-p) * mid >= (y - x)) {
                        ans = (mid * q - y);
                        hi = mid - 1;
                    } else {
                        lo = mid + 1;
                    }
                }

                in.println(ans);


            }

        }

        in.flush();
        in.close();
    }




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


        Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){
            @Override
            public void run() {
                solve();
            }
        };

        t.start();
        t.join();

    }

    private static class Kattio extends PrintWriter {
 
        private BufferedReader r;
        private String line;
        private StringTokenizer st;
        private String token;
        
        public Kattio(InputStream i) {
            super(new BufferedOutputStream(System.out));
            r = new BufferedReader(new InputStreamReader(i));
        }
        public Kattio(InputStream i, OutputStream o) {
            super(new BufferedOutputStream(o));
            r = new BufferedReader(new InputStreamReader(i));
        }
 
        public boolean hasNext() {
            return peekToken() != null;
        }
 
        public int nextInt() {
            return Integer.parseInt(nextToken());
        }
 
        public double nextDouble() { 
            return Double.parseDouble(nextToken());
        }
 
        public long nextLong() {
            return Long.parseLong(nextToken());
        }
 
        public String next() {
            return nextToken();
        }
        
        public String nextLine() {
            token = null;
            st = null;
            try {
                return r.readLine();
            } catch (IOException e) {
                return null;
            }
        }
 
        private String peekToken() {
            if (token == null) 
                try {
                    while (st == null || !st.hasMoreTokens()) {
                        line = r.readLine();
                        if (line == null) return null;
                        st = new StringTokenizer(line);
                    }
                    token = st.nextToken();
                } catch (IOException e) { }
            return token;
        }
 
        private String nextToken() {
            String ans = peekToken();
            token = null;
            return ans;
        }
    }
}
