> #include<stdio.h>
> #include<math.h>
> #include<stdlib.h>
> #include<iostream>
> #include<algorithm>
> #include<cmath>
> using namespace std;
> struct Point
> {
>     double left;
>     double right;
>     
> }p[5012];
> bool cmp(Point a,Point b)
> {
>     return a.left<b.left;
> }
> int main()
> {
>    int  i,j,n,m;
>    int r;
>    int o=0;
>    while(~scanf("%d%d",&n,&r),n,r)
>    {
>      int a,b;
>      bool flag=true;
>     
>      for(i=0;i<n;i++)
>      {
>      scanf("%d%d",&a,&b);
>      if(abs(b)>r)
>       {
>             flag=false;
>       }
>       p[i].left=a*1.000-sqrt(r*r*1.00-b*b*1.0000);
>       p[i].right=a*1.000+sqrt(r*r*1.00-b*b*1.0000);
>      }
>       printf("Case %d: ",++o);
>      if(flag==false)
>        puts("-1");
>      else
>      {
>        sort(p,p+n,cmp);
>        int cnt=1;
>        double temp=p[0].right;
>        for(i=1;i<n;i++)
>        {
>             if(p[i].right<temp)
>             {
>                 temp=p[i].right;
>             }
>             else if(p[i].left>temp)
>             {
>                 cnt++;
>                 temp=p[i].right;
>             }
>        }
>        printf("%d\n",cnt);
>      }
>    }
> }