Go: package main

import (
	"bufio"
	"os"
	"math"
	"strings"
	"strconv"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

const (
	INF = 0x7FFFFFFF
	EPS = 1e-10
)

type Point struct {
	x, y float64
}
func (p *Point) plus(q *Point) *Point {
	return &Point{p.x + q.x, p.y + q.y}
}
func (p *Point) minus(q *Point) *Point {
	return &Point{p.x - q.x, p.y - q.y}
}
func (p *Point) multi(a float64) *Point {
	return &Point{p.x * a, p.y * a}
}
func (p *Point) div(a float64) *Point {
	return &Point{p.x / a, p.y / a}
}
func (p *Point) abs() float64 {
	return math.Sqrt(p.norm())
}
func (p *Point) norm() float64 {
	return p.x*p.x + p.y*p.y
}
func (p *Point) isLessThan(q *Point) bool {
	if p.x != q.x {
		return p.x < q.x && p.y < q.y
	}
	return true
}
func (p *Point) isEqual(q *Point) bool {
	return math.Abs(p.x - q.x) < EPS && math.Abs(p.y - q.y) < EPS
}

type Segment struct {
	p1, p2 *Point
}
func (s *Segment) norm() float64 {
	return (s.p2.x - s.p1.x)*(s.p2.x - s.p1.x) +
		(s.p2.y - s.p1.y)*(s.p2.y - s.p1.y)
}
func (s *Segment) abs() float64 {
	return math.Sqrt(s.norm())
}

func norm(a *Point) float64 {
	return a.x*a.x + a.y*a.y
}

func abs(a *Point) float64 {
	return math.Sqrt(norm(a))
}

func polar(a, r float64) *Point {
	return &Point{math.Cos(r)*a, math.Sin(r)*a}
}

func getDistance(a, b *Point) float64 {
	return abs(a.minus(b))
}

func dot(a, b *Point) float64 {
	return a.x*b.x + a.y*b.y
}

func cross(a, b *Point) float64 {
	return a.x*b.y - a.y*b.x
}

func getDistanceLP(s Segment, p *Point) float64 {
	return cross(s.p2.minus(s.p1), p.minus(s.p1))/ abs(s.p2.minus(s.p1))
}

func getDistanceSP(s Segment, p *Point) float64 {
	if dot(s.p2.minus(s.p1), p.minus(s.p1)) < 0 {
		return abs(p.minus(s.p1))
	}
	if dot(s.p1.minus(s.p2), p.minus(s.p2)) < 0 {
		return abs(p.minus(s.p2))
	}
	return getDistanceLP(s, p)
}

func main() {
	for scanner.Scan() {
		buf := strings.Split(scanner.Text(), " ")
		R, _ := strconv.Atoi(buf[0])
		N, _ := strconv.Atoi(buf[1])
		if R == 0 && N == 0 {
			break
		}
		p := make([]*Point, N)
		r := make([]float64, N)
		v := make([]float64, N)
		d := make([]float64, N)
		nd := make([]float64, N)
		die := make([]bool, N)
		for i := 0; i < N; i++ {
			scanner.Scan()
			buf_ := strings.Split(scanner.Text(), " ")
			_x, _ := strconv.ParseFloat(buf_[0], 64)
			_y, _ := strconv.ParseFloat(buf_[1], 64)
			_r, _ := strconv.ParseFloat(buf_[2], 64)
			_v, _ := strconv.ParseFloat(buf_[3], 64)
			tmp := &Point{_x, _y}
			p[i] = tmp
			r[i] = _r
			v[i] = _v
			nd[i] = getDistance(p[i], &Point{0, 0})
			d[i] = getDistance(p[i], &Point{0, 0})
			die[i] = false
		}
		for {
			for i := 0; i < N; i++ {
				nd[i] = math.Max(float64(R), nd[i]-v[i])
			}
			mini := float64(INF)
			id := -1
			for i := 0; i < N; i++ {
				if die[i] {
					continue
				}
				if nd[i] < EPS+float64(R) {
					continue
				}
				if nd[i] > mini {
					continue
				}
				mini = nd[i]
				id = i
			}
			if id == -1 {
				break
			}
			s := Segment{p[id], p[id]}
			s.p1 = s.p1.div(d[id])
			s.p1 = s.p1.multi(float64(R))
			s.p2 = s.p2.div(d[id])
			s.p2 = s.p2.multi(10000000.0)
			for i := 0; i < N; i++ {
				if nd[i] < EPS + float64(R) {
					continue
				}
				a := p[i]
				a = a.div(d[i])
				a = a.multi(nd[i])
				if getDistanceSP(s, a) < EPS + r[i] {
					die[i] = true
				}
			}
		}
		ans := 0
		for i := 0; i < N; i++ {
			if !die[i] {
				ans++
			}
		}
		fmt.Println(ans)
	}
}

C++: #include<iostream>
#include<cmath>
#include<vector>
#include<algorithm>
#include<iomanip>
#include<cassert>
#include<cstdlib>
#include<complex>
#define REP(i,s,n) for(int i=s;i<n;i++)
#define rep(i,n) REP(i,0,n)
#define inf (1<<29)
#define EPS (1e-8)
#define COUNTER_CLOCKWISE 1
#define CLOCKWISE -1 
#define ONLINE_BACK 2
#define ONLINE_FRONT -2
#define ON_SEGMENT 0
#define equals(a,b) (fabs((a)-(b)) < EPS)
#define MAX 110
using namespace std;

// template
class Point
{
  public:
  double x,y;

  Point(double x = -inf,double y = -inf): x(x),y(y){}

  Point operator + (Point p ){return Point(x+p.x,y+p.y);}
  Point operator - (Point p){return Point(x-p.x,y-p.y);}
  Point operator * (double a){return Point(a*x,a*y);}
  Point operator / (double a){return Point(x/a,y/a);}

  bool operator < (const Point& p) const{ return !equals(x,p.x)?x<p.x:y<p.y; }

};

struct Segment
{
  Point p1,p2;
  Segment(Point p1 = Point(-1,-1),Point p2 = Point(-1,-1)):p1(p1),p2(p2){}
};
typedef Point Vector;
typedef Segment Line;
typedef vector<Point> Polygon;

double dot(Point a,Point b){ return a.x*b.x + a.y*b.y; }

double cross(Point a,Point b){ return a.x*b.y - a.y*b.x; }

double norm(Point a){ return a.x*a.x+a.y*a.y; }

bool point_equals(Point a,Point b){ return equals(a.x,b.x) && equals(a.y,b.y); }

Point rotate(Point a,double rad){ return Point(cos(rad)*a.x - sin(rad)*a.y,sin(rad)*a.x + cos(rad)*a.y); }

double toRad(double agl){ return agl*M_PI/180.0; }

int ccw(Point p0,Point p1,Point p2)
{
  Point a = p1-p0;
  Point b = p2-p0;
  if(cross(a,b) > EPS)return COUNTER_CLOCKWISE;
  if(cross(a,b) < -EPS)return CLOCKWISE;
  if(dot(a,b) < -EPS)return ONLINE_BACK;
  if(norm(a) < norm(b))return ONLINE_FRONT;
  return ON_SEGMENT;
}

double abs(Point a){ return sqrt(norm(a)); }

double getDistanceLP(Line s,Point p){ return abs(cross(s.p2-s.p1,p-s.p1))/abs(s.p2-s.p1); }

double getDistanceSP(Segment s,Point p)
{
  if(dot(s.p2-s.p1,p-s.p1) < 0.0)return abs(p-s.p1);
  if(dot(s.p1-s.p2,p-s.p2) < 0.0)return abs(p-s.p2);
  return getDistanceLP(s,p);
}

//cross product of pq and pr
double cross3p(Point p,Point q,Point r)
{
  return (r.x-q.x) * (p.y -q.y) - (r.y - q.y) * (p.x - q.x);
}
  
//returns true if point r is on the same line as the line pq
bool collinear(Point p,Point q,Point r)
{
  return fabs(cross3p(p,q,r)) < EPS;
}
  
//returns true if point t is on the left side of line pq
bool ccwtest(Point p,Point q,Point r)
{
  return cross3p(p,q,r) > 0;//can be modified to accept collinear points
}
 
bool onSegment(Point p,Point q,Point r)
{
  return collinear(p,q,r) && equals(sqrt(pow(p.x-r.x,2)+pow(p.y-r.y,2)) + sqrt(pow(r.x-q.x,2) + pow(r.y-q.y,2) ),sqrt(pow(p.x-q.x,2)+pow(p.y-q.y,2)) ) ;
}


//--------------------------------------------------------------------------

struct UFO
{
  Point p;
  double r,v;
  UFO(Point p=Point(),double r=-inf,double v=-inf):p(p),r(r),v(v){}
};

double R;
int N;
UFO ufo[MAX];
bool alive[MAX];

int main()
{
  int rx;
  while(cin >> rx >> N,rx|N)
    {
      R = (double)rx;
      rep(i,N)
	{
	  cin >> ufo[i].p.x >> ufo[i].p.y >> ufo[i].r >> ufo[i].v;
	  alive[i] = true;
	}

      int pass = 0;	

      while(true)
	{
	  int nearest = -inf;
	  rep(i,N)
	    {
	      if(!alive[i])continue;
	      double arg = atan2(ufo[i].p.y,ufo[i].p.x);
	      Point e = ufo[i].p/abs(ufo[i].p);
	      Point next = Point(ufo[i].p.x-ufo[i].v*e.x,ufo[i].p.y-ufo[i].v*e.y);
	      double dist_next = abs(next);
	      //cout << i << " next( " << next.x << "," << next.y << ")" << endl;
	      if( onSegment(next,ufo[i].p,Point(0,0))|| (equals(dist_next,R) || dist_next < R))
		{
		  alive[i] = false;
		  pass++;
		  continue;
		}
	      ufo[i].p = next;
	      if(nearest == -inf)nearest = i;
	      else
		{
		  double d1 = abs(ufo[nearest].p);
		  double d2 = abs(ufo[i].p);
		  if(!equals(d1,d2) && d1 > d2)nearest = i;
		}
	    }
	  /*
	  rep(i,N)
	    {
	      cout << "ufo[" << i << "] = (" << ufo[i].p.x << "," << ufo[i].p.y << ")" << endl;
	    }
	  */ 
	  if(nearest == -inf)break;
	  Vector e = ufo[nearest].p/abs(ufo[nearest].p);
	  Line line = Line(Point(0,0),e*1000000);
	  rep(i,N)
	    {
	      if(!alive[i])continue;

	      double dist = getDistanceSP(line,ufo[i].p);
	      if(equals(dist,ufo[i].r) || dist < ufo[i].r)
		{
		  alive[i] = false;
		  continue;
		}
	    }

	}
      cout << pass << endl;
    }
  return 0;
}