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 Problems1 {

    public static void main(String[] args) throws IOException {
      FastScanner sc=new FastScanner(System.in);
      int n=sc.nextInt();
      int x,y,p,q;
      long ans;
      for(int i=0;i<n;i++){
          x=sc.nextInt(); y=sc.nextInt();
          p=sc.nextInt(); q=sc.nextInt();
          
          ans=-1;
          long f=1,l = 1000000000,med;
          long pp,qq;
          long xc ,yc;
          for(int b=0;b<1000 && f<=l;b++){
              med=(f+l)/2;
              pp=med*p;
              qq=med*q;
              
              if(x>pp || y>qq){
                  f=med+1;
                  continue;        
              }
              xc=pp-x;
              if(y+xc>qq){
                  f=med+1;
                  continue;
              }
              yc=qq-y-xc;
              ans=xc+yc;
              l=med-1;
              
          }
          System.out.println(ans);
      }
      

    }
    public static void dis(int a[]){
        StringBuilder s=new StringBuilder();
        for(int i=0;i<a.length;i++){
            s.append(a[i]+" ");
        }
        System.out.println(s.toString());
    }
    //__________________________________________________________
    static class FastScanner {
	    BufferedReader br;
	    StringTokenizer st;
		
	    public FastScanner(InputStream i) {
	        br = new BufferedReader(new InputStreamReader(i));
	        st = new StringTokenizer("");
	    }
				
	    public String next() throws IOException {
	        if(st.hasMoreTokens())
	            return st.nextToken();
	        else
	            st = new StringTokenizer(br.readLine());
	        return next();
	    }

	    public int nextInt() throws IOException {
	        return Integer.parseInt(next());
	    }
	    //#
	    public long nextLong() throws IOException {
	        return Long.parseLong(next());
	    }
	    public double nextDouble() throws IOException {
	        return Double.parseDouble(next());
	    }
	    //$
	}
}
