> #include <iostream>
> #include <stdio.h>
> #include <algorithm>
> #include <deque>
> using namespace std;
> 
> struct pt{
> 	int x,y;
> }points[120];
> 
> int ptNum[120];
> int ptHeng[120];
> int ptList[120][120];
> 
> int n,r;
> 
> bool compare(const pt &p1, const pt &p2){
> 	return p1.x<p2.x || (p1.x==p2.x && p1.y<p2.y);
> }
> 
> int main() {
> 	int t;
> 	scanf("%d", &t);
> 	for(int ii = 0; ii < t; ii++){
> 		scanf("%d%d", &n, &r);
> 		for(int j = 0; j < n; j++){
> 			scanf("%d%d", &points[j].x, &points[j].y);
> 		}
> 		sort(points, points+n, compare);
> 		int hzb = -1;
> 		int cnt = -1;
> 		for(int i = 0; i < n; i++){
> 			if(points[i].x == hzb){
> 				ptList[cnt][ptNum[cnt]] = points[i].y;
> 				ptNum[cnt]++;
> 			}
> 			else{
> 				hzb = points[i].x;
> 				cnt++;
> 				ptNum[cnt] = 1;
> 				ptList[cnt][0] = points[i].y;
> 				ptHeng[cnt] = hzb;
> 			}
> 		}
> 		cnt++;
> 		int ans = 0;
> 		for(int i = 0; i < cnt; i++){
> 			int collect[120], tot = 0;
> 			int startP = i;
> 			while(startP < cnt && ptHeng[startP] <= ptHeng[i]+r){
> 				for(int j = 0; j < ptNum[startP]; j++){
> 					collect[tot] = ptList[startP][j];
> 					tot++;
> 				}
> 				startP++;
> 			}
> 			if(tot <= ans) continue;
> 			sort(collect, collect+tot);
> 			int gs = 0;
> 			int mxGs = 0;
> 			deque<int> fangye;
> 			for(int j = 0; j < tot; j++){
> 				fangye.push_back(collect[j]);
> 				gs++;
> 				while(collect[j]-fangye.front() > r){
> 					fangye.pop_front();
> 					gs--;
> 				}
> 				if(gs > mxGs) mxGs = gs;
> 			}
> 			if(mxGs > ans) ans = mxGs;
> 		}
> 		printf("%d\n", ans);
> 	}
> 	return 0;
> }