#include <iostream>
#include <complex>
#include <vector>

using namespace std;

#define REP(i,n) for(int i = 0; i < (int)(n); i++)
#define FOR(i,c) for(__typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define ALLOF(c) (c).begin(), (c).end()

typedef complex<int> P;
struct C {
    P p;
    int r;
};

istream& operator>>(istream& is, P& p) {
    int x, y;
    is >> x >> y;
    p = P(x, y);
    return is;
}

bool cp_contains(const C& c, const P& p) {
    return (norm(c.p-p) < c.r*c.r);
}

bool cc_contains(const C& c1, const C& c2) {
    return (c1.r > c2.r && norm(c1.p-c2.p) < (c1.r-c2.r)*(c1.r-c2.r));
}

bool cc_outside(const C& c1, const C& c2) {
    return (norm(c1.p-c2.p) > (c1.r+c2.r)*(c1.r+c2.r));
}

int search(int i, const vector<C>& cs, const P& s, const P& t, vector<int>& memo) {
    const int n = cs.size();
    int& res = memo[i];
    if (res < 0) {
        if (cp_contains(cs[i], s) == cp_contains(cs[i], t)) {
            res = 0;
        }
        else if (cp_contains(cs[i], s)) {
            res = 1;
            REP(j, n) {
                if ((cp_contains(cs[j], s) && !cp_contains(cs[j], t) && cc_contains(cs[j], cs[i])) ||
                    (!cp_contains(cs[j], s) && cp_contains(cs[j], t) && cc_outside(cs[j], cs[i]))) {
                    res = max(res, 1+search(j, cs, s, t, memo));
                }
            }
        }
        else { // cp_contains(cs[i], t)
            res = 1;
            REP(j, n) {
                if (!cp_contains(cs[j], s) && cp_contains(cs[j], t) && cc_contains(cs[i], cs[j])) {
                    res = max(res, 1+search(j, cs, s, t, memo));
                }
            }
        }
    }
    return res;
}

int main() {

    int n;
    P s, t;
    while(cin >> n >> s >> t && !(n == 0)) {
        vector<C> cs(n);
        REP(i, n) {
            C& c = cs[i];
            cin >> c.p >> c.r;
        }

        int res = 0;
        vector<int> memo(n, -1);
        REP(k, n)
            res = max(res, search(k, cs, s, t, memo));

        cout << res << endl;
    }

    return 0;
}