/*  This Code is Submitted by wywcgs for Problem 1019 on 2005-12-23 at 00:16:59 */ 
#include <cstdio>
#include <algorithm>
using namespace std;

const int MAX = 128;

class Tree {
public:
	int x, y;
	void init();
	bool in(int, int, int, int) const;
};
void Tree::init() {
	scanf("%d %d", &x, &y);
}
bool Tree::in(int l, int r, int u, int d) const {
	return (l <= x && x <= r && u <= y && y <= d);
}

int main()
{
	Tree tree[MAX];
	int n, l;
	int i, j, t, T;
	
	scanf("%d", &T);
	for(t = 0; t < T; t++) {
		scanf("%d %d", &n, &l);
		for(i = 0; i < n; i++) {
			tree[i].init();
		}
		int most = 0;
		for(i = 0; i < n; i++) {
			int a = 0, b = 0, c = 0, d = 0;
			for(j = 0; j < n; j++) {
				if(tree[j].in(tree[i].x, tree[i].x+l, tree[i].y-l, tree[i].y)) a++;
				if(tree[j].in(tree[i].x-l, tree[i].x, tree[i].y-l, tree[i].y)) b++;
				if(tree[j].in(tree[i].x, tree[i].x+l, tree[i].y, tree[i].y+l)) c++;
				if(tree[j].in(tree[i].x-l, tree[i].x, tree[i].y, tree[i].y+l)) d++;
			}
			most = max(most, a); most = max(most, b); 
			most = max(most, c); most = max(most, d);
		}
		printf("%d\n", most);
	}
	
	return 0;
}