Description

N (1 <= N <= 1,000) calves try out for the Moo U gymnastics team this year, each with a positive integer height and a weight less than 100,000. Your goal is to select a team of as many calves as possible from this group. There is only one constraint the team must satisfy: the height H and weight W of each calf on the team must obey the following inequality:

A*(H-h) + B*(W-w) <= C

where h and w are the minimum height and weight values over all calves on the team, and A, B and C are supplied positive integral constants less than 10,000. Compute the maximum number of calves on the team.

Input

* Line 1: A single integer, N

* Line 2: Three space-separated integers, A, B and C

• Lines 3..N+2: Two space-separated integers: respectively the height and weight of a calf

Output

* Line 1: One integer, the maximum number of calves on the team.

8
1 2 4
5 1
3 2
2 3
2 1
7 2
6 4
5 1
4 3

5

Hint

Calves 1, 2, 3, 4 and 7, for example, form a legal team. A larger team is impossible.

Source

USACO 2004 March Green