Madara, as you know, is not generally a person to work-out. But recently his girlfriend told him to get in shape. So he started going to the gym everyday.
He knows that he must do at least N number of push-ups in a day. If he is unable to do N push-ups altogether, he does them in different sets. He knows he can do at max A push-ups in the same set. Every time he does a set, he becomes a little tired and hence does D number of push-ups less in the next set. But no matter how tired he gets, he is capable of doing M number of push-ups at the least.
What is the minimum number of sets in which Madara can complete his daily goal?
INPUT:
The first line contains an Integer T, the number of test cases. Each test case consists of four integers - N, A, D and M.
OUTPUT:
For each test case, output an single Integer denoting the minimum number of sets on a new line.
CONSTRAINTS:
1 <= T <= 100
1 <= A, N <=1000
1 <= D <= 500
5 <= M <= 100
In the first test case, in the first set he can do 20 push-ups, in the second set, he can do 19, in the third set he will do 18. Thus doing a total of 57 push-ups in 3 sets, which fulfills his daily requirement of at least 50 push-ups.