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.text.DecimalFormat;
import java.util.*;
import java.io.*;
import java.math.*;

import javax.swing.plaf.basic.BasicInternalFrameTitlePane.MaximizeAction;

public class Main {
	public static long mod = (long) (1e9 + 7);
	static InputReader s;
	static PrintWriter out;
	public static void main(String args[]) {
		new Thread(null, new Runnable() {
			public void run() {
				try {
					solve();
					out.flush();
					out.close();
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		}, "1", 1 << 26).start();
	}

	public static void solve() throws IOException {
		s = new InputReader(System.in);
		OutputStream outputStream = System.out;
		out = new PrintWriter(outputStream);
		Scanner sc = new Scanner(System.in);
		int t=s.nextInt();
		while(t-->0){
			long x=s.nextLong();
			long y=s.nextLong();
			long p=s.nextLong();
			long q=s.nextLong();
			if((p==q && x!=y) || (p==0 && x!=0)){
				out.println("-1");
			}
			else{
				long l=0,h=(long)1e9;
				while(l<=h){
					long m=(l+h)/2;
					if(m*p-x<=m*q-y && m*p-x>=0){
						h=m-1;
					}
					else{
						l=m+1;
					}
				}
				out.println(l*q-y);
			}
		}
	}
	
	static long combinations(long n, long r) { // O(r)
		if (r == 0 || r == n)
			return 1;
		r = Math.min(r, n - r);
		long ans = n; // nC1=n;
		for (int i = 1; i < r; i++) {
			ans = (ans * (n - i));
			 ans= ans/(i+1);
//			ans = (ans * modulo(i + 1, mod - 2, mod)) % mod;
		}
		return ans;
	}

	static long modulo(long x, long y, long p) {
		long res = 1;
		x = x % p;

		while (y > 0) {
			if (y % 2 == 1)
				res = (res * x) % p;

			y = y >> 1;
			x = (x * x) % p;
		}
		return res;
	}

	static HashSet<Integer> primeFactors(int n) // O(sqrt(n))
	{
		// Print the number of 2s that divide n
		HashSet<Integer> arr = new HashSet<>();
		while (n % 2 == 0) {
			arr.add(2);
			n = n / 2;
		}

		// n must be odd at this point. So we can skip one element (Note i = i
		// +2)
		for (int i = 3; i <= Math.sqrt(n); i = i + 2) {
			// While i divides n, print i and divide n
			while (n % i == 0) {
				arr.add(i);
				n = n / i;
			}
		}
		// This condition is to handle the case when n is a prime number
		// greater than 2
		if (n > 2)
			arr.add(n);

		return arr;
	}

	public static long expo(long a, long b) {
		if (b == 0)
			return 1;
		if (b == 1)
			return a;
		if (b == 2)
			return a * a;

		if (b % 2 == 0) {
			return expo(expo(a, (b / 2)), 2);
		} else {
			return a * expo(expo(a, (b - 1) / 2), 2);
		}
	}

	static class Pair implements Comparable<Pair> {
		char a;
		String b;

		// int c;
		Pair(char aa, String bb) {
			a = aa;
			b = bb;
			// c=cc;
		}

		public int compareTo(Pair o) {
			int ans = this.b.compareTo(o.b);
			return ans;
			// return ans==0 ? -Integer.compare(this.b, o.b):ans;
			// if(Long.compare(this.x, o.x)!=0)
			// return -Long.compare(this.x, o.x);
			// else
			// return Long.compare(this.y, o.y);
			// return Integer.compare(this.x, o.x);
			// return Long.compare(this.x, o.x);
		}

//		public int hashCode() {
//			int hu = (int) (a ^ (a >>> 32));
//			int hv = (int) (b ^ (b >>> 32));
//			return 31 * hu + hv;
//		}

		//
		public boolean equals(Object o) {
			Pair other = (Pair) o;
			return a == other.a && b == other.b;
		}

		public String toString() {
			return "[x=" + a + ", y=" + b + "]";
		}

	}

	public static int[] sieve(int N) { // O(n*log(logn))
		int arr[] = new int[N + 1];
		for (int i = 2; i <= Math.sqrt(N); i++) {
			if (arr[i] == 0) {
				for (int j = i * i; j <= N; j = j + i) {
					arr[j] = 1;
				}
			}
		}
		return arr;
		// All the i for which arr[i]==0 are prime numbers.
	}

	static int gcd(int a, int b) { // O(logn)
		if (b == 0)
			return a;
		return gcd(b, a % b);
	}

	public static void debug(Object... o) {
		System.out.println(Arrays.deepToString(o));
	}

	static void catalan_numbers(int n) {
		long catalan[] = new long[n + 1];
		catalan[1] = 1;
		for (int i = 2; i <= n; i++) {
			for (int j = 1; j <= i - 1; j++) {
				catalan[i] = catalan[i] + ((catalan[j]) * catalan[i - j]);
			}
		}
	}

	static final class InputReader {
		private final InputStream stream;
		private final byte[] buf = new byte[1024];
		private int curChar;
		private int Chars;

		public InputReader(InputStream stream) {
			this.stream = stream;
		}

		private int read() throws IOException {
			if (curChar >= Chars) {
				curChar = 0;
				Chars = stream.read(buf);
				if (Chars <= 0)
					return -1;
			}
			return buf[curChar++];
		}

		public final int nextInt() throws IOException {
			return (int) nextLong();
		}

		public final long nextLong() throws IOException {
			int c = read();
			while (isSpaceChar(c)) {
				c = read();
				if (c == -1)
					throw new IOException();
			}
			boolean negative = false;
			if (c == '-') {
				negative = true;
				c = read();
			}
			long res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += (c - '0');
				c = read();
			} while (!isSpaceChar(c));
			return negative ? (-res) : (res);
		}

		public final int[] nextIntBrray(int size) throws IOException {
			int[] arr = new int[size];
			for (int i = 0; i < size; i++)
				arr[i] = nextInt();
			return arr;
		}

		public final String next() throws IOException {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			StringBuilder res = new StringBuilder();
			do {
				res.append((char) c);
				c = read();
			} while (!isSpaceChar(c));
			return res.toString();
		}

		public final String nextLine() throws IOException {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			StringBuilder res = new StringBuilder();
			do {
				res.append((char) c);
				c = read();
			} while (c != '\n' && c != -1);
			return res.toString();
		}

		private boolean isSpaceChar(int c) {
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}
	}
}