Unknown to us ignorant humans, potatoes have learnt how to access the internet! In fact, they have even built major civilisations in desolate places of Africa with dozens and dozens of potatoes growing there. In every such potato civilisation, there will be N potatoes living in the PotatoTown.
In order to allow some of the potatoes to access the internet, there will be a WiFi hotspot in the top-left corner of the city, which is at coordinate (0, 0). This WiFi hotspot has a range of R units. You will be provided with a set of coordinates describing where the N potatoes are growing. Calculate the number of potatoes that can access the internet from the WiFi hotspot.
The first line of input will contain two integers, N and R.
The next N lines of input will contain two integers each, describing the x and y coordinate of one of the potatoes.
Your output should contain one integer, the number of potatoes that can access the internet.
Your output should terminate with a newline.
Subtask 1 (35%): 1 <= N, Xi, Yi <= 1 000
Subtask 2 (65%): 1 <= N, Xi, Yi <= 1 000 000
Sample Input 1
Sample Output 1
Sample Input 2
Sample Output 2