#include<algorithm>

#include<iostream>

#include<cstdio>

#include<cmath>

using namespace std;

struct Radar {

    double start,end;

} radar[];

bool cmp(Radar a,Radar b) {

    return a.start<b.start;

}

int main() {

    int n,d,x,y,m,num,flag;

    double l,r;

    m = ;

    while(scanf("%d%d",&n,&d)) {

        if(!n && !d)  //如果为0

            break;

        flag = true;

        for(int i = ; i < n; i++) {

            scanf("%d%d",&x,&y);

            if(y > d)

                flag = false;

            radar[i].start = x - sqrt(d * d - y * y);  //勾股定理

            radar[i].end = x + sqrt(d * d - y * y);  //区间覆盖范围

        }

        if(!flag) {

            printf("Case %d: -1\n",m++);

            continue;

        }

        sort(radar,radar + n,cmp);   //排序  n为岛屿数目

        num = ,l = radar[].start,r = radar[].end;//l和r是double  l为最左端的区间的左端  r为右端

        for(int i = ; i < n; i++) {

            if(radar[i].start >= l && radar[i].end <= r) { // 某两块区间存在包含关系

                l = radar[i].start;

                r = radar[i].end;

            } else if(radar[i].start <= r && radar[i].end >= r) //某两个区间交叉

                l = radar[i].start;

            else if(radar[i].start > r) { //两个区间没有交集

                l = radar[i].start;

                r = radar[i].end;

                num++;

            }

        }

        printf("Case %d: %d\n",m++,num);

    }

    return ;

}