프로그램 명: ceoi_photo
제한시간: 1 초

Task

You are given a photo of the skyline of Targu-Mures taken during the night. Some rooms still have the light on. You know that all the buildings can be modeled by rectangles of surface area at most A. Find the minimum number of buildings that can lead to the picture.

Specifically, you are given an integer A, and N points at integer coordinates (x,y). You must find a minimum number of rectangles that have one side on the x-axis and area at most A, which cover all points. The rectangles may overlap.

입력

The first line of the input will contain two integers N and A, separated by a single space. The next N lines will contain two integers x and y, representing the coordinates of each point.

출력

The output should consist of exactly one line containing the minimum number of rectangles.

Constraints

입출력 예

입력

6 4
2 1
4 1
5 1
5 4
7 1
6 4

출력

3


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출처:ceoi/2009/

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