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 <algorithm>
#include <cctype>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <string>
#include <vector>

using namespace std;

#define reps(i,f,n) for(int i=f; i<int(n); ++i)
#define rep(i,n) reps(i,0,n)

typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;

const double EPS = 1e-8;
const int INF = 1001001001;

typedef complex<double> P;
struct L : public vector<P> {
	L(const P &a, const P &b){
		push_back(a);
		push_back(b);
	}
};
double cross(const P& a, const P& b){
	return imag(conj(a)*b);
}
double dot(const P& a, const P& b){
	return real(conj(a)*b);
}
P projection(const L& l, const P& p){
	double t = dot(p-l[0], l[0]-l[1]) / norm(l[0]-l[1]);
	return l[0] + t*(l[0]-l[1]);
}
bool intersectSP(const L& s, const P& p){
	return abs(s[0]-p) + abs(s[1]-p) - abs(s[1]-s[0]) < EPS;
}
double distanceSP(const L& s, const P& p){
	const P r = projection(s, p);
	if(intersectSP(s, r)) return abs(r - p);
	return min(abs(s[0]-p), abs(s[1]-p));
}

struct UFO
{
	int r;
	P x, v;
	bool alive;
	UFO() : alive(true) {}
};

int main()
{
	double R;
	int n;
	while(scanf("%lf%d", &R, &n), n){
		UFO ufo[100];
		rep(i, n){
			double x0, y0, v;
			scanf("%lf%lf%d%lf", &x0, &y0, &ufo[i].r, &v);
			ufo[i].x = P(x0, y0);
			if(norm(ufo[i].x) > EPS)
				ufo[i].v = -v*ufo[i].x/abs(ufo[i].x);
			else
				ufo[i].v = P(0.0, 0.0);
		}
		
		int cnt = 0;
		for(;;){
			int nearest = -1;
			rep(i, n){
				if(ufo[i].alive){
					if(norm(ufo[i].x) > norm(ufo[i].v))
						ufo[i].x += ufo[i].v;
					else
						ufo[i].x = P(0.0, 0.0);
					
					if(abs(ufo[i].x) < R+EPS){
						ufo[i].alive = false;
						++cnt;
					}
					else if(nearest==-1 || norm(ufo[nearest].x) > norm(ufo[i].x))
						nearest = i;
				}
			}
			if(nearest == -1)
				break;
			
			L beam(R*ufo[nearest].x/abs(ufo[nearest].x), 10000.0*ufo[nearest].x);
			rep(i, n){
				if(!ufo[i].alive)
					continue;
				if(distanceSP(beam, ufo[i].x) < ufo[i].r + EPS){
					ufo[i].alive = false;
				}
			}
		}
		printf("%d\n", cnt);
	}
	return 0;
}

C++: from math import sqrt,cos,atan2

class Ufo:
	def __init__(self,px,py,d,vd,ui):
		self.pd=sqrt(px**2+py**2)
		self.px=float(px)
		self.py=float(py)
		self.fpd=self.pd
		self.fpx=self.px
		self.fpy=self.py
		self.ex=self.fpx/self.fpd
		self.ey=self.fpy/self.fpd
		self.d=float(d)
		self.vd=float(vd)
		self.vx=-self.vd*self.ex
		self.vy=-self.vd*self.ey
		self.i=ui
	def move(self):
		self.pd -= self.vd
		self.px += self.vx
		self.py += self.vy



while True:
	R,ul=tuple(map(int,raw_input().split()))
	if(R==0 and ul==0): break
	us=[]
	for ui in xrange(ul):
		px,py,d,vd = tuple(map(int,raw_input().split()))
		u = Ufo(px,py,d,vd,ui)
		us.append(u)

	re=0
	while True:
		for u in us: u.move()
		us.sort(key=lambda u: u.pd)

		for u in us[:]:
			if u.pd<=R:
				re+=1
				us.remove(u)
				#print u.i, "due to invade"
				continue
			else:
				break
		if len(us)==0: break

		neu=us.pop(0)
		#print "focus",neu.i
		#print neu.i,"due to hit"

		for u in us[:]:
			d = u.pd*abs(neu.fpx*u.fpy-neu.fpy*u.fpx)/neu.fpd/u.fpd	#u kara laser ni orosita suisen no nagasa
			if d<u.d:
				if u.pd*cos(atan2(u.fpy,u.fpx)-atan2(neu.fpy,neu.fpx)) + sqrt(u.d**2-d**2) > R:
					us.remove(u)
					#print u.i, "due to hit"
		if len(us)==0: break

	print re