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.InputStream;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class C412 {
	public static void main(String[] args) {
		FS scan = new FS(System.in);
		int T = scan.nextInt();
		for(int t=1;t<=T;t++){
			long x = scan.nextLong(), y = scan.nextLong(), p = scan.nextLong(), q = scan.nextLong();
			
			
			long gcd = gcd(x,y);
			long ta = x/gcd, tb = y/gcd;
			if(ta==p&&tb==q){
				System.out.println(0);
				continue;
			}
			
			if(p==1&&q==1){
				System.out.println(-1);
				continue;
			}
			
			long lo = (long)Math.ceil(y/(double)q), hi = (long)1e10, sol = -1;
			while(lo<=hi){
				long mid = lo+hi>>1;
				long steps = q*mid-y;
				long top = p*mid-x;
				
				if(top<0||top>steps||steps<0){
					lo = mid+1;
				}else{
					sol = steps;
					hi = mid-1;
				}
			}
			
			System.out.println(sol);
		}
	}
	
	private static long gcd(long a, long b) {
		return b==0?a:gcd(b,a%b);
	}
	private static class FS {
		BufferedReader br;
		StringTokenizer st;
		public FS(InputStream in) {
			br = new BufferedReader(new InputStreamReader(in));
		}
		String next(){
			while(st==null||!st.hasMoreElements()){
				try{st = new StringTokenizer(br.readLine());}
				catch(IOException e){e.printStackTrace();}
			}
			return st.nextToken();
		}
		int nextInt() {return Integer.parseInt(next());}
		long nextLong() {return Long.parseLong(next());}
		double nextDouble() { return Double.parseDouble(next());}
	}
}
