画图，每个给出点都有对应区间；先sort，再尽量靠右选；很常见的套路了..//注意不要越界（0，L）

struct Q //复习结构
{
double l,r;
Q(double _l,double _r):l(_l),r(_r){}
bool operator < (const Q &a) const {
return r<a.r;
}
};

#include
#include
#include
#include
#include
#include
using namespace std;
struct village
{
double l,r;
village(double _l,double _r):l(_l),r(_r){}
bool operator < (const village &a) const { return rvec;
int length,D,n;

void dist(int x,int y,double &l,double &r)
{
l=(double)x-sqrt((double)D*(double)D-(double)y*(double)y);
r=(double)x+sqrt((double)D*(double)D-(double)y*(double)y);
}

int main()
{
int x,y;
double l,r;
while(scanf("%d",&length)!=EOF)
{
scanf("%d%d",&D,&n);
vec.clear();
for(int i=;ivec[i].r){
++ans;
temp=vec[i].r;
}
}
printf("%d\n",ans);
}
return ;
}