#include<iostream>

 #include<stdio.h>

 #include<string.h>

 #include<map>

 #include<vector>

 #include<set>

 #include<stack>

 #include<queue>

 #include<algorithm>

 #include<cmath>

 #include<stdlib.h>

 using namespace std;

 #define MAX(a,b) (a > b ? a : b)

 #define MIN(a,b) (a < b ? a : b)

 #define MAXN  10000001

 #define INF 1000000007

 #define mem(a) memset(a,0,sizeof(a))

 #define eps 1e-15

 struct node{double s,t;}ma[];

 double R;

 int N;

 const int island_max=;

 void get_len(int index,double a,double b)

 {

     double temp = sqrt(R*R - b*b);

     ma[index].s=a-temp;

     ma[index].t=a+temp;

 }

 int cmp(node a,node b)

 {

     if(a.t!=b.t)return (a.t < b.t);

     return (b.s > a.s);

 }

 int main()

 {

     int ca = ;

     while(~scanf("%d%lf",&N,&R) && (N || R))

     {

         int i;

         double a,b;

         int flag = ;

         for(i=;i<N;i++)

         {

             scanf("%lf %lf",&a,&b);

             if(b<=R && !flag)

             {

                 get_len(i,a,b);

             }

             else flag = ;

         }

         if(flag){printf("Case %d: -1\n",ca++);continue;}

         sort(ma,ma+N,cmp);

         double key = ma[].t;

         int ans=;

         for(i=;i<N;i++)

         {

             if(ma[i].s-key >eps)

             {

                 key = ma[i].t;

                 ans ++;

             }

         }

          printf("Case %d: %d\n",ca++,ans);

     }

     return ;

 }