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.InputStream;
import java.io.PrintStream;
import java.util.Scanner;

/**
 */
public class MainC {
	public static void main(String[] args) {
		run(System.in, System.out);
	}

	public static void run(InputStream in, PrintStream out) {

		try (Scanner sc = new Scanner(in)) {
			int n = sc.nextInt();
			for (int i = 0; i < n; i++) {
				long x = sc.nextLong();
				long y = sc.nextLong();
				long p = sc.nextLong();
				long q = sc.nextLong();
				out.println(go(x, y, p, q));

			}

		}
	}

	private static long go(long x, long y, long p, long q) {
		System.err.println("Doing " + x + "/" + y + "/" + p + "/" + q);
		if (p == q) {
			if (x < y) return -1;
			else if (x == 0) return 1;
			else return 0;
		}
		if (p == 0) {
			if (x == 0) return 0;
			else return -1;
		}

		if (x * q == p * y) return 0;

		long min = 0;
		long max = (int) 1e9;
		
		while (min < max) {
			long n = (min + max) / 2;
			if (q * n < y ||  p * n < x) {
				min = n + 1;
				continue;
			}
			long a = p * n - x;
			long b = q * n - y;
			if (a <= b) max = n;
			else min = n + 1;
		}
		return q * min - y;

	}

}