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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;


/**
 *
 * @author sss
 */
public class Test{
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws IOException {
        BufferedReader vod=new BufferedReader(new InputStreamReader(System.in));
        int n=Integer.parseInt(vod.readLine());
        StringTokenizer s;
        for (int i=0; i<n; i++){
            s=new StringTokenizer(vod.readLine());
            int x=Integer.parseInt(s.nextToken());
            int y=Integer.parseInt(s.nextToken());
            int p=Integer.parseInt(s.nextToken());
            int q=Integer.parseInt(s.nextToken());
            if ((p==q&&x!=y)||(p==0&&x!=0)){
                System.out.println(-1);
                continue;
            }
            long l=0,r=(long) 1e9;
            while (l<=r){
                long m=(l+r)/2;
                if (p*m-x>=0&&p*m-x<=q*m-y){
                    r=m-1;
                }
                else{
                    l=m+1;
                }
            }
            System.out.println(q*l-y);
        }
    }
}