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 ? 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 ≤ 10 9 ; 0 ≤ p ≤ q ≤ 10 9 ; 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. 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. 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.