1 #include<cstdio>
2 #include<cstdlib>
3 #include<cstring>
4 #include<algorithm>
5 #include<math.h>
6
7 const int MAXN=10000;
8 using namespace std;
9 struct node
10 {
11 double x1,x2;
12 } p[MAXN];
13 bool cmp(node a,node b)
14 {
15 return a.x2<b.x2;
16 }
17 int main()
18 {
19 int n,m,ii=0;
20 double x,y;
21 while(scanf("%d%d",&n,&m))
22 {
23 ii++;
24 if(n==0&&m==0) break;
25 int flag=0;
26 for(int i=0; i<n; i++)
27 {
28 scanf("%lf%lf",&x,&y);
29 if(fabs(y)>m) flag=1;
30 double c=sqrt(m*m-y*y);
31 p[i].x1=x+c;
32 p[i].x2=x-c;
33 }
34 if(flag==1)
35 {
36 printf("Case %d: %d\n",ii,-1);
37 continue;
38 }
39 sort(p,p+n,cmp);
40 double c=p[0].x1;
41 int t=1;
42 for(int i=1; i<n; i++)
43 {
44 if(p[i].x1<c)
45 {
46 c=p[i].x1;
47 }
48 else if(p[i].x2>c)
49 {
50 t++;
51 c=p[i].x1;
52 }
53 }
54 printf("Case %d: %d\n",ii,t);
55 }
56 return 0;
57 }
