Dave

Recently, Dave is boring, so he often walks around. He finds that some places are too crowded, for example, the ground. He couldn't help to think of the disasters happening recently. Crowded place is not safe. He knows there are N (1<=N<=1000) people on the ground. Now he wants to know how many people will be in a square with the length of R (1<=R<=1000000000). (Including boundary).

The input contains several cases. For each case there are two positive integers N and R, and then N lines follow. Each gives the (x, y) (1<=x, y<=1000000000) coordinates of people.

Output the largest number of people in a square with the length of R.

3 2
1 1
2 2
3 3

3

If two people stand in one place, they are embracing.

The 36th ACM/ICPC Asia Regional Dalian Site —— Online Contest