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 C implements Runnable {
	FastReader scn;
	PrintWriter out;
	String INPUT = "";

	void solve() {
		int t = scn.nextInt();
		while (t-- > 0) {
			long x = scn.nextInt(), y = scn.nextInt(), p = scn.nextInt(), q = scn.nextInt();
			long g = gcd(x, y);
			x /= g;
			y /= g;

			if (p == 1 && q == 1 && x < y) {
				out.println(-1);
				continue;
			}

			if (p == x && y == q) {
				out.println(0);
				continue;
			}

			x *= g;
			y *= g;

			long add = 0;
			if (y < q) {
				add = q - y;
				y = q;
			}
			long st = q * ((y + q - 1) / q);

			long l = 0, r = (long) 1e18, d = -1;
			while (l <= r) {
				long m = (l + r) >> 1;
				if(st + q * 1.0 * m > 1e18) {
					r = m - 1;
					continue;
				}
				long s = st + q * m;
				long diff = s - y + add;
				long num = (s / q) * p;
				if (num >= x && num - x <= diff) {
					d = diff;
					r = m - 1;
				} else {
					l = m + 1;
				}
			}

			out.println(d);
		}
	}

	long gcd(long a, long b) {
		return b == 0 ? a : gcd(b, a % b);
	}

	public void run() {
		long time = System.currentTimeMillis();
		boolean oj = System.getProperty("ONLINE_JUDGE") != null;
		out = new PrintWriter(System.out);
		scn = new FastReader(oj);
		solve();
		out.flush();
		if (!oj) {
			System.out.println(Arrays.deepToString(new Object[] { System.currentTimeMillis() - time + " ms" }));
		}
	}

	public static void main(String[] args) {
		new Thread(null, new C(), "Main", 1 << 26).start();
	}

	class FastReader {
		InputStream is;

		public FastReader(boolean onlineJudge) {
			is = onlineJudge ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		}

		byte[] inbuf = new byte[1024];
		public int lenbuf = 0, ptrbuf = 0;

		int readByte() {
			if (lenbuf == -1)
				throw new InputMismatchException();
			if (ptrbuf >= lenbuf) {
				ptrbuf = 0;
				try {
					lenbuf = is.read(inbuf);
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (lenbuf <= 0)
					return -1;
			}
			return inbuf[ptrbuf++];
		}

		boolean isSpaceChar(int c) {
			return !(c >= 33 && c <= 126);
		}

		int skip() {
			int b;
			while ((b = readByte()) != -1 && isSpaceChar(b))
				;
			return b;
		}

		double nextDouble() {
			return Double.parseDouble(next());
		}

		char nextChar() {
			return (char) skip();
		}

		String next() {
			int b = skip();
			StringBuilder sb = new StringBuilder();
			while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b != ' ')
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		}

		String nextLine() {
			int b = skip();
			StringBuilder sb = new StringBuilder();
			while ((!isSpaceChar(b) || b == ' ')) { // when nextLine, (isSpaceChar(b) && b != ' ')
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		}

		char[] next(int n) {
			char[] buf = new char[n];
			int b = skip(), p = 0;
			while (p < n && !(isSpaceChar(b))) {
				buf[p++] = (char) b;
				b = readByte();
			}
			return n == p ? buf : Arrays.copyOf(buf, p);
		}

		int nextInt() {
			int num = 0, b;
			boolean minus = false;
			while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
				;
			if (b == '-') {
				minus = true;
				b = readByte();
			}

			while (true) {
				if (b >= '0' && b <= '9') {
					num = num * 10 + (b - '0');
				} else {
					return minus ? -num : num;
				}
				b = readByte();
			}
		}

		long nextLong() {
			long num = 0;
			int b;
			boolean minus = false;
			while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
				;
			if (b == '-') {
				minus = true;
				b = readByte();
			}

			while (true) {
				if (b >= '0' && b <= '9') {
					num = num * 10 + (b - '0');
				} else {
					return minus ? -num : num;
				}
				b = readByte();
			}
		}

		char[][] nextMatrix(int n, int m) {
			char[][] map = new char[n][];
			for (int i = 0; i < n; i++)
				map[i] = next(m);
			return map;
		}

		int[] nextIntArray(int n) {
			int[] a = new int[n];
			for (int i = 0; i < n; i++)
				a[i] = nextInt();
			return a;
		}

		long[] nextLongArray(int n) {
			long[] a = new long[n];
			for (int i = 0; i < n; i++)
				a[i] = nextLong();
			return a;
		}

		int[][] next2DInt(int n, int m) {
			int[][] arr = new int[n][];
			for (int i = 0; i < n; i++) {
				arr[i] = nextIntArray(m);
			}
			return arr;
		}

		long[][] next2DLong(int n, int m) {
			long[][] arr = new long[n][];
			for (int i = 0; i < n; i++) {
				arr[i] = nextLongArray(m);
			}
			return arr;
		}

		int[] shuffle(int[] arr) {
			Random r = new Random();
			for (int i = 1, j; i < arr.length; i++) {
				j = r.nextInt(i);
				arr[i] = arr[i] ^ arr[j];
				arr[j] = arr[i] ^ arr[j];
				arr[i] = arr[i] ^ arr[j];
			}
			return arr;
		}

		int[] uniq(int[] arr) {
			Arrays.sort(arr);
			int[] rv = new int[arr.length];
			int pos = 0;
			rv[pos++] = arr[0];
			for (int i = 1; i < arr.length; i++) {
				if (arr[i] != arr[i - 1]) {
					rv[pos++] = arr[i];
				}
			}
			return Arrays.copyOf(rv, pos);
		}

		int[] reverse(int[] arr) {
			int l = 0, r = arr.length - 1;
			while (l < r) {
				arr[l] = arr[l] ^ arr[r];
				arr[r] = arr[l] ^ arr[r];
				arr[l] = arr[l] ^ arr[r];
				l++;
				r--;
			}
			return arr;
		}
	}
}