#include <bits/stdc++.h> 
 
using namespace std;
 
int a[201][201];
int b[201][201][101];
int n, k, Max = -1;
struct point
{
	int x, y;
};
 
inline int search(int x, int y, int c)
{
	if (b[x][y][c] == -1)
	{
		b[x][y][c] = 0;
		if (a[x+1][y] == 1)
			b[x][y][c] = max(search(x+1,y,c),b[x][y][c]);
		else if (c < k)
			b[x][y][c] = max(search(x+1,y,c+1),b[x][y][c]);
		if (a[x][y+1] == 1)
			b[x][y][c] = max(search(x,y+1,c),b[x][y][c]);
		else if (c < k)
			b[x][y][c] = max(search(x,y+1,c+1),b[x][y][c]);
		b[x][y][c] += 1; 
	}
	return b[x][y][c];
}
 
int main()
{
	freopen("csp2022pj_point.in","r",stdin);
	freopen("csp2022pj_point.out","w",stdout);
 	
 	cin >> n >> k;
 	for (int i = 1; i <= 200; ++i)
 		for (int j = 1; j <= 200; ++j)
 			a[i][j] = 0;
 			
 	for (int i = 1; i <= 200; ++i)
 		for (int j = 1; j <= 200; ++j)
 			for (int l = 0; l <= k; ++l)
 				b[i][j][l] = -1;
 	
	vector<point> v(n+1);		
 	for (int i = 1; i <= n; ++i)
 	{
 		cin >> v[i].x >> v[i].y;
 		a[v[i].x][v[i].y] = 1;
	}
	for (int i = 1; i <= n; ++i)
		Max = max(search(v[i].x,v[i].y,0),Max);
		
	cout << Max;
	
	return 0;
}