 Problems

# Skyscrapers

Time limit 1 second
Memory limit 128 MiB

5000 years later, when the coronavirus epidemic was stopped, n skyscrapers are planned to be built in Baku. We will represent Baku as the coordinate axis of numbers. For each skyscraper, its coordinate (x[i]) and height (h[i]) are given. Engineers consider the skyscraper "unprofitable" if to the left of it at a distance of no more than d, and also to the right of it at a distance of no more than d, there is a skyscraper which height is at least twice more than the height of a given skyscraper (this skyscraper itself may be unprofitable). Such skyscrapers are considered unsuccessful from a business point of view, so engineers plan to build some other facility instead. You must calculate the number of "unprofitable" skyscrapers so that the engineers know their job.

## Input data

First line contains two numbers n (1n10^5) and d (1d10^9). Next d lines contain integers x[i] and h[i] (1x[i], h[i]10^9 ). All coordinates of skyscrapers are different.

## Output data

Print the number of unprofitable skyscrapers.

## Examples

Input example #1
6 4
10 3
6 2
5 3
9 7
3 6
11 2
Output example #1
2