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<stdio.h>
#include<algorithm>
#include<math.h>
using namespace std;
double eps=1e-9;
double PI=acos(-1.0);
double x[110];
double y[110];
double r[110];
double th[110];
double v[110];
double d[110];
int in[110];
int main(){
	int a,b;
	while(scanf("%d%d",&a,&b),a){
		int ret=0;
		for(int i=0;i<b;i++)in[i]=0;
		int rem=b;
		for(int i=0;i<b;i++){
			scanf("%lf%lf%lf%lf",x+i,y+i,r+i,v+i);
			th[i]=atan2(y[i],x[i]);
			d[i]=sqrt(x[i]*x[i]+y[i]*y[i]);
			if(x[i]*x[i]+y[i]*y[i]<eps+a*a){
				in[i]=1;
				ret++;
				rem--;
			}
		}
		while(rem){
			double val=999999999;
			int at=-1;
			for(int i=0;i<b;i++){
				if(in[i])continue;
				d[i]-=v[i];
				if(d[i]<eps+a){
					in[i]=1;
					ret++;
					rem--;
				}else if(val>d[i]){
					val=d[i];at=i;
				}
			}
			if(!~at)break;
			for(int i=0;i<b;i++){
				if(in[i])continue;
				if(x[i]*x[at]+y[i]*y[at]<0){
					if(d[i]<r[i]+eps){
						in[i]=1;rem--;
					}
					continue;
				}
				double X=d[i]*cos(th[i]);
				double Y=d[i]*sin(th[i]);
				double d2=(y[at]*X-x[at]*Y)*(y[at]*X-x[at]*Y)/(x[at]*x[at]+y[at]*y[at]);
				if(d2<r[i]*r[i]+eps){
					in[i]=1;
					rem--;
				}
			}
		}
		printf("%d\n",ret);
	}
	
}

C++: #include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <cassert>
#include <iostream>
#include <cctype>
#include <sstream>
#include <string>
#include <list>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <map>
#include <utility>
#include <numeric>
#include <algorithm>
#include <iterator>
#include <bitset>
#include <complex>
#include <fstream>
using namespace std;
typedef long long ll;
const double EPS = 1e-9;
typedef vector<double> vdouble;
typedef pair<double, double> pdouble;
#define rep(i, n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define MSG(a) cout << #a << " " << a << endl;
#define REP(i, x, n) for(double i = x; i < n; i++)
template<class T> T RoundOff(T a){ return double(a+.5-(a<0)); }
template<class T, class C> void chmax(T& a, C b){ if(a < b) a = b; }
template<class T, class C> void chmin(T& a, C b){ if(b < a) a = b; }
template<class T, class C> pair<T, C> mp(T a, C b){ return make_pair(a, b); }

typedef complex<double> P;

struct Enemy 
{	
	P p;
	double r, v;
};

bool operator < (Enemy right, Enemy left)
{	return abs(right.p) < abs(left.p);	}

// OÏ
double cross(P a, P b)
{	return a.real() * b.imag() - b.real() * a.imag();	}

// àÏ
double dot(P a, P b)
{	return a.real() * b.real() + a.imag() * b.imag();	}

// _ÆüªÌ£
double dist(P a, P b, P c)
{
	if(dot(b - a, c - a) < EPS) return abs(c - a);
	if(dot(a - b, c - b) < EPS) return abs(c - b);
	
	return abs(cross(b - a, c - a)) / abs(b - a);
}

// ap ©ç av ÖÌüªª cp É é¼a r Ì~ÆÕË·é©Ç¤©
bool hit(P ap, P av, P cp, double r)
{
	return dist(ap, av, cp) - r <= EPS;	
}

int main()
{
    int N, R;
    while(cin >> R >> N && (N || R))
    {
        vector<Enemy> enemy(N);
        
        rep(i, N) cin >> enemy[i].p.real() >> enemy[i].p.imag() >> enemy[i].r >> enemy[i].v;
		
        
        int res = 0;
        
		while(!enemy.empty())
        {
			// iR
			for(short i = enemy.size() - 1; 0 <= i; i--)
			{				
				// Ú®üªøÍ«EÆÕË·éÈçJEg
				if(abs(enemy[i].p) - enemy[i].v - R <= EPS)
				{
					enemy.erase(enemy.begin() + i);
					res++;
				}
				
				// enemy[i].p = polar(abs(enemy[i].p) - enemy[i].v, arg(enemy[i].p));
				enemy[i].p += (-enemy[i].p / abs(-enemy[i].p)) * enemy[i].v;
			}
			
			// WI
			P aim(polar(10000.0, arg((*min_element(ALL(enemy))).p)));

            
            // UÎÛÉÆËAÆËüãÌGðê|
			for(short i = enemy.size() - 1; 0 <= i; i--)
            {
				// ÄµÄ¢­
				if(hit(P(0, 0), aim, enemy[i].p, enemy[i].r))
				{
					enemy.erase(enemy.begin() + i);
				}
			}
        }
        
        cout << res << endl;

    }
}