#include <iostream>
#include <cmath>
#include <algorithm>

using namespace std;

#define MAXP 1100

int N, d;
typedef struct POINT{
	int x, y; 	//location
	double s, e;	//start and end position of interval
};
POINT p[MAXP];

int CMP(const void *a, const void *b){
	POINT x = *(POINT*)a;
	POINT y = *(POINT*)b;	
	if(x.s > y.s)return 1;
	return -1;
}

//count the interval of x-position
void cnt_interval(int index){
	double y = (double)p[index].y;
	double x = pow(d * d - y * y, 0.5);
	p[index].s = (double)p[index].x - x;
	p[index].e = (double)p[index].x + x;	
}

//count the minimum points that can cover all the points
int count(){
	int i, cnt = 1;	
	//record the right end
	double e = p[0].e; 
	for(i = 0;i < N; i++){
		//overlap
		if(p[i].s <= e)
			e = min(e, p[i].e);
		else{
			cnt++;
			e = p[i].e;
		}
	}			
	return cnt;
}

int main(){
	int i, j, cases = 0;
	bool nosol;
	while(1){
		scanf("%d %d", &N, &d);
		if(!N && !d) break;

		//initial
		nosol = false;
		memset(p, 0, sizeof(p));
		
		//read file
		for(i = 0;i < N; i++){
			scanf("%d %d", &p[i].x, &p[i].y);
			
			//count the interval
			cnt_interval(i);
			
			//if the point is to far from the distance
			if(p[i].y > d)
				nosol = true;
		}

		//if no solution
		if(nosol){
			printf("Case %d: -1\n", ++cases);
			continue;
		}

		//sort the x-axis
		qsort(p, N, sizeof(POINT), CMP);			
		
		//print the answer
		printf("Case %d: %d\n", ++cases, count());
		
	}
	return 0;
}