Given $n$ points on a two-dimensional coordinate system. Find a square with side length $k$ and sides parallel to the x-axis or y-axis such that it contains the maximum number of points.
### Input
- The first line contains two integers $n$ and $k$.
- The next $n$ lines each contain two integers $(x, y)$, representing a point at coordinates $(x, y)$.
### Output
- Print an integer representing the maximum number of points in a square with side length $R$.
### Constraints
- $1 \leq n \leq 10^5$.
- $1 \leq x, y \leq 10^5$.
### Example
Input:
```
4 2
1 1
1 4
3 2
4 3
```
Output:
```
2
```
