#include <bits/stdc++.h>
using namespace std;
#define FOR(i,k,n) for(int i = (int)(k); i < (int)(n); i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(a) a.begin(), a.end()
#define MS(m,v) memset(m,v,sizeof(m))
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<string> vs;
typedef pair<int, int> pii;
const int MOD = 1000000007;
const int INF = MOD + 1;
const ld EPS = 1e-12;
template<class T> T &chmin(T &a, const T &b) { return a = min(a, b); }
template<class T> T &chmax(T &a, const T &b) { return a = max(a, b); }

/*--------------------template--------------------*/
typedef long double ld;
const ld PI = acos(-1.0);
bool eq(ld a, ld b) { return abs(a - b) < EPS; }
typedef complex<ld> Point;
typedef vector<Point> Polygon;

namespace std
{
	bool operator < (const Point& a, const Point& b)
	{
		return real(a) != real(b) ? real(a) < real(b) : imag(a) < imag(b);
	}
}

struct Line
{
	Point a, b;
	Line(Point p, Point q) :a(p), b(q) {};
	Line(ld x1, ld y1, ld x2, ld y2) :a(Point(x1, y1)), b(Point(x2, y2)) {};
};

struct Circle
{
	Point p; ld r;
	Circle(Point a, ld b) :p(a), r(b) {};
};

ld dot(Point a, Point b)
{
	return real(conj(a)*b);
}

ld cross(Point a, Point b)
{
	return imag(conj(a)*b);
}

int ccw(Point a, Point b, Point c)
{
	b -= a; c -= a;
	if (cross(b, c) > EPS) return 1;    //counter cloclwise
	if (cross(b, c) < -EPS) return -1;  //cloclwise
	if (dot(b, c) < 0) return 2;        //c--a--b on line 
	if (norm(b) < norm(c)) return -2;   //a--b--c on line
	return 0;                           //a--c--b on line
}

bool isis_ll(Line l, Line m)
{
	return abs(cross(l.b - l.a, m.b - m.a)) > EPS;
}

bool isis_ls(Line l, Line s)
{
	return cross(l.b - l.a, s.a - l.a)*cross(l.b - l.a, s.b - l.a) < EPS;
}

bool isis_ss(Line s, Line t)
{
	return (ccw(s.a, s.b, t.a)*ccw(s.a, s.b, t.b) <= 0 &&
		ccw(t.a, t.b, s.a)*ccw(t.a, t.b, s.b) <= 0);
}

bool isis_lp(Line l, Point p)
{
	return (abs(cross(l.b - p, l.a - p)) < EPS);
}

bool isis_sp(Line s, Point p)
{
	return (abs(s.a - p) + abs(s.b - p) - abs(s.b - s.a)) < EPS;
}

Point projection(Line l, Point p)
{
	Point base = l.b - l.a;
	ld r = dot(p - l.a, base) / norm(base);
	return l.a + base*r;
}

Point mirror(Line l, Point p)
{
	return Point(2, 0)*projection(l, p) - p;
}

ld dist_lp(Line l, Point p)
{
	return abs(p - projection(l, p));
}

ld dist_ll(Line l, Line m)
{
	return isis_ll(l, m) ? 0 : dist_lp(l, m.a);
}

ld dist_ls(Line l, Line s)
{
	if (isis_ls(l, s)) return 0;
	return min(dist_lp(l, s.a), dist_lp(l, s.b));
}

ld dist_sp(Line s, Point p)
{
	Point r = projection(s, p);
	if (isis_sp(s, r)) return abs(r - p);
	return min(abs(s.a - p), abs(s.b - p));
}

ld dist_ss(Line s, Line t)
{
	if (isis_ss(s, t)) return 0;
	return min(min(dist_sp(s, t.a), dist_sp(s, t.b)), min(dist_sp(t, s.a), dist_sp(t, s.b)));
}

Point is_ll(Line s, Line t)
{
	ld a = cross(s.b - s.a, t.b - t.a);
	ld b = cross(s.b - s.a, s.b - t.a);
	return t.a + b / a*(t.b - t.a);
}

vector<Point> is_cc(Circle c1, Circle c2)
{
	vector<Point> res;
	ld d = abs(c1.p - c2.p);
	ld rc = (d*d + pow(c1.r, 2) - pow(c2.r, 2)) / (2 * d);
	ld dfr = pow(c1.r, 2) - rc*rc;
	if (abs(dfr) < EPS) dfr = 0;
	if (dfr < 0.0) return res;
	ld rs = sqrt(dfr);
	Point diff = (c2.p - c1.p) / d;
	res.push_back(c1.p + diff*Point(rc, rs));
	if (dfr != 0.0) res.push_back(c1.p + diff*Point(rc, -rs));
	return res;
}

int isis_cc(Circle c1, Circle c2)
{
	ld d = abs(c1.p - c2.p);
	if (d - c1.r - c2.r > EPS) return -2; //separate
	if (abs(d - c1.r - c2.r) < EPS) return -1; //circumscribe
	if (c1.r < c2.r) swap(c1, c2);
	if (abs(d - c1.r + c2.r) < EPS) return 1;//inscribe
	if (c1.r - d - c2.r > EPS) return 2;//involve
	else return 0;//intersect
}

bool contain_cp(Circle c, Point p)
{
	return c.r - abs(c.p - p) > EPS;
}

vector<vi> g[2];
vi mx[2];
int dp[2][1111];

int get_max(int i, int t)
{
	if (dp[i][t] >= 0) return dp[i][t];
	int res = 1;
	int tmp = 0;
	for (auto j : g[i][t])
	{
		chmax(tmp, get_max(i, j));
	}
	return dp[i][t] = res + tmp;
}

int main()
{
	cin.sync_with_stdio(false); cout << fixed << setprecision(10);
	int n;
	while (cin >> n, n)
	{
		MS(dp, -1);
		ld sx, sy, gx, gy; cin >> sx >> sy >> gx >> gy;
		Point st(sx, sy), go(gx, gy);
		vector<Circle> v[2];
		REP(i, n)
		{
			ld x, y, r; cin >> x >> y >> r;
			Circle c(Point(x, y), r);
			bool f1 = contain_cp(c, st);
			bool f2 = contain_cp(c, go);
			if (f1 && !f2) v[0].push_back(c);
			if (!f1 && f2) v[1].push_back(c);
		}
		REP(i, 2)
		{
			g[i].clear();
			g[i].resize(v[i].size());
			mx[i].clear();
			mx[i].resize(v[i].size());
		}
		REP(k, 2)REP(i, v[k].size())REP(j, v[k].size())
		{
			if (i == j) continue;
			if (isis_cc(v[k][i], v[k][j]) == 2 && v[k][i].r > v[k][j].r)
			{
				g[k][i].push_back(j);
			}
		}
		REP(i, 2)REP(j, v[i].size())
		{
			mx[i][j] = get_max(i, j);
		}
		int ans = 0;
		REP(i, 2)
		{
			if (mx[i].empty()) continue;
			chmax(ans, *(max_element(ALL(mx[i]))));
		}
		REP(i, v[0].size())REP(j, v[1].size())
		{
			if (isis_cc(v[0][i], v[1][j]) != -2) continue;
			chmax(ans, mx[0][i] + mx[1][j]);
		}
		cout << ans << endl;
	}
	return 0;
}

Measured memory_bytes: 5940