I want to eat chicken

Building 301 at Seoul National University hides a fried chicken shop called Nupchicken. Every time you order a chicken there, the shop hands you $C$ coupons, and $F$ coupons buy one free chicken.

Dooyoung is not a regular, so a chicken he orders with coupons comes with no coupons at all. Sangeon is a regular, and the owner gives him coupons even for a chicken ordered with coupons.

Sangeon and Dooyoung each have $M$ won, and one chicken costs $P$ won. Each of them orders as many chickens as his money allows and takes a free chicken every time he has collected $F$ coupons. Find how many more chickens Sangeon eats than Dooyoung.

The first line contains the number of test cases $T$ ($1 \le T \le 20{,}000$). The $T$ test cases follow.

Each test case is one line with four integers: the price of one chicken $P$ ($1 \le P \le 50{,}000$), the money available for chicken $M$ ($1 \le M \le 1{,}000{,}000$), the number of coupons needed for one free chicken $F$ ($2 \le F \le 1{,}000$), and the number of coupons given for one ordered chicken $C$ ($1 \le C < F$), in that order.

For each test case, print on its own line how many more chickens Sangeon eats than Dooyoung.