#include <bits/stdc++.h>

using namespace std;

const double EPS = 1e-8, PI = acos(-1);

inline bool eq(double a, double b) { return abs(b - a) < EPS; }

#define curr(P, i) P[i]
#define next(P, i) P[(i+1)%P.size()]
#define prev(P, i) P[(i+P.size()-1) % P.size()]
enum
{
  OUT, ON, IN
};
namespace Geometry
{
  struct Point
  {
    double x, y;

    Point() {};

    Point(double x, double y) : x(x), y(y) {};

    Point operator+(const Point &b) const { return Point(x + b.x, y + b.y); }

    Point operator-(const Point &b) const { return Point(x - b.x, y - b.y); }

    Point operator*(const double b) const { return Point(x * b, y * b); }

    Point operator*(const Point &b) const { return Point(x * b.x - y * b.y, x * b.y + y * b.x); }

    Point operator/(const double b) const { return Point(x / b, y / b); }

    bool operator<(const Point &b) const { return x != b.x ? x < b.x : y < b.y; }

    bool operator==(const Point &b) const { return eq(x, b.x) && eq(y, b.y); }

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

    double arg() { return atan2(x, y); }

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

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

    Point rotate90() { return Point(-y, x); }

    friend ostream &operator<<(ostream &os, Point &p) { return os << "(" << p.x << "," << p.y << ")"; }

    friend istream &operator>>(istream &is, Point &a) { return is >> a.x >> a.y; }
  };

  struct Line
  {
    Point a, b;

    Line() {};

    Line(Point a, Point b) : a(a), b(b) {};

    friend ostream &operator<<(ostream &os, Line &p) { return os << "(" << p.a.x << "," << p.a.y << ") to (" << p.b.x << "," << p.b.y << ")"; }

    friend istream &operator>>(istream &is, Line &a) { return is >> a.a.x >> a.a.y >> a.b.x >> a.b.y; }
  };

  struct Segment
  {
    Point a, b;

    Segment() {};

    Segment(Point a, Point b) : a(a), b(b) {};

    friend ostream &operator<<(ostream &os, Segment &p) { return os << "(" << p.a.x << "," << p.a.y << ") to (" << p.b.x << "," << p.b.y << ")"; }

    friend istream &operator>>(istream &is, Segment &a) { return is >> a.a.x >> a.a.y >> a.b.x >> a.b.y; }
  };

  struct Circle
  {
    Point p;
    double r;

    Circle() {};

    Circle(Point p, double r) : p(p), r(r) {};
  };

  typedef vector< Point > Polygon;
  typedef vector< Segment > Segments;
  typedef vector< Line > Lines;
  typedef vector< Circle > Circles;
  typedef pair< Point, Point > PointPoint;

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

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

  int ccw(const Point &a, Point b, Point c)
  {
    b = b - a, c = c - a;
    if(cross(b, c) > EPS) return +1;  // a ??? b ??§ ???????¨??????????????????? c
    if(cross(b, c) < -EPS) return -1; // a ??? b ??§ ????¨??????????????????? c
    if(dot(b, c) < 0) return +2;  // c -- a -- b??§?????´??????
    if(b.norm() < c.norm()) return -2; // a -- b -- c??§?????´??????
    return 0;  // a -- c -- b??§?????´??????
  }

  Point Projection(const Line &l, const Point &p)
  {
    double t = dot(p - l.a, l.a - l.b) / (l.a - l.b).norm();
    return l.a + (l.a - l.b) * t;
  }

  Point Projection(const Segment &l, const Point &p)
  {
    double t = dot(p - l.a, l.a - l.b) / (l.a - l.b).norm();
    return l.a + (l.a - l.b) * t;
  }

  Point Reflection(const Line &l, const Point &p)
  {
    return p + (Projection(l, p) - p) * 2.0;
  }

  double Distance(const Line &l, const Point &p)
  { //OK
    return (p - Projection(l, p)).abs();
  }

  bool Intersect(const Line &l, const Line &m)
  {
    return abs(cross(l.b - l.a, m.b - m.a)) > EPS || abs(cross(l.b - l.a, m.b - l.a)) < EPS;
  }

  bool Intersect(const Line &l, const Segment &s)
  {
    return cross(l.b - l.a, s.a - l.a) * cross(l.b - l.a, s.b - l.a) < EPS;
  }

  bool Intersect(const Line &l, const Point &p)
  {
    return abs(ccw(l.a, l.b, p)) != -1;
  }

  bool Intersect(const Segment &s, const Segment &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 Intersect(const Segment &s, const Point &p)
  {
    return ccw(s.a, s.b, p) == 0;
  }

  bool Intersect(const Circle &c, const Line &l)
  {
    return Distance(l, c.p) <= c.r + EPS;
  }

  bool Intersect(const Circle &c, const Point &p)
  {
    return abs((p - c.p).abs() - c.r) < EPS;
  }

  int Intersect(const Circle &c, const Segment &l)
  {
    if((Projection(l, c.p) - c.p).norm() - c.r * c.r > EPS) return 0;
    const double d1 = (c.p - l.a).abs(), d2 = (c.p - l.b).abs();
    if(d1 < c.r + EPS && d2 < c.r + EPS) return 0;
    if(d1 < c.r - EPS && d2 > c.r + EPS || d1 > c.r + EPS && d2 < c.r - EPS) return 1;
    const Point h = Projection(l, c.p);
    if(dot(l.a - h, l.b - h) < 0) return 2;
    return 0;
  }

  bool Intersect(const Circle &a, const Circle &b)
  {
    return ((a.p - b.p).norm() - (a.r + b.r) * (a.r + b.r) < EPS) &&
           ((a.p - b.p).norm() - (a.r - b.r) * (a.r - b.r) > -EPS);
  }

  double Distance(const Segment &s, const Point &p)
  {
    Point r = Projection(s, p);
    if(Intersect(s, r)) return (r - p).abs();
    return min((s.a - p).abs(), (s.b - p).abs());
  }

  double Distance(const Segment &a, const Segment &b)
  {
    if(Intersect(a, b)) return 0;
    return min(min(Distance(a, b.a), Distance(a, b.b)), min(Distance(b, a.a), Distance(b, a.b)));
  }

  double Distance(const Line &l, const Line &m)
  {
    return Intersect(l, m) ? 0 : Distance(l, m.a);
  }

  double Distance(const Line &l, const Segment &s)
  { //OK
    if(Intersect(l, s)) return 0;
    return min(Distance(l, s.a), Distance(l, s.b));
  }

  double Distance(const Point &a, const Point &b)
  { //OK
    return (a - b).abs();
  }

  Point Crosspoint(const Segment &l, const Segment &m)
  { //OK
    double A = cross(l.b - l.a, m.b - m.a);
    double B = cross(l.b - l.a, l.b - m.a);
    if(abs(A) < EPS && abs(B) < EPS) return m.a; // same line
    return m.a + (m.b - m.a) * B / A;
  }

  PointPoint Crosspoint(const Circle &c, const Line l)
  {
    Point hp = Projection(l, c.p), h = hp - c.p;
    const double d2 = h.norm();
    Point v = (l.b - l.a) * sqrt(c.r * c.r - d2) / (l.b - l.a).abs();
    return PointPoint(hp - v, hp + v);
  }

  PointPoint Crosspoint(const Circle &c, const Segment &l)
  {
    Line aa = Line(l.a, l.b);
    if(Intersect(c, l) == 2) return Crosspoint(c, aa);
    PointPoint ret = Crosspoint(c, aa);
    if(dot(l.a - ret.first, l.b - ret.first) < 0) ret.second = ret.first;
    else ret.first = ret.second;
    return ret;
  }

  PointPoint Crosspoint(const Circle &c1, const Circle &c2)
  {
    double d = (c1.p - c2.p).abs();
    double a = acos((c1.r * c1.r + d * d - c2.r * c2.r) / (2 * c1.r * d));
    double t = atan2(c2.p.y - c1.p.y, c2.p.x - c1.p.x);
    Point p1 = c1.p + Point(cos(t + a) * c1.r, sin(t + a) * c1.r);
    Point p2 = c1.p + Point(cos(t - a) * c1.r, sin(t - a) * c1.r);
    return (PointPoint(p1, p2));
  }

  bool parallel(const Line &a, const Line &b)
  {
    return abs(cross(a.b - a.a, b.b - b.a)) < EPS;
  }

  bool orthogonal(const Line &a, const Line &b)
  {
    return abs(dot(a.a - a.b, b.a - b.b)) < EPS;
  }

  int Contains(const Polygon &Q, const Point &p)
  {
    bool in = false;
    for(int i = 0; i < Q.size(); i++) {
      Point a = curr(Q, i) - p, b = next(Q, i) - p;
      if(a.y > b.y) swap(a, b);
      if(a.y <= 0 && 0 < b.y && cross(a, b) < 0) in = !in;
      if(cross(a, b) == 0 && dot(a, b) <= 0) return ON;
    }
    return in ? IN : OUT;
  }

  bool Contains(const Circle &c, const Point &p)
  {
    return (c.p - p).abs() < c.r + EPS;
  }

  double Area2(const Polygon &p)
  { //OK
    double A = 0;
    for(int i = 0; i < p.size(); ++i) {
      A += cross(curr(p, i), next(p, i));
    }
    return A;
  }

  bool IsConvex(const Polygon &p)
  {
    for(int i = 0; i < p.size(); i++) {
      if(ccw(prev(p, i), curr(p, i), next(p, i)) == -1) return false;
    }
    return true;
  }

  Polygon Convex_Hull(Polygon &p)
  {
    int n = p.size(), k = 0;
    if(n >= 3) {
      sort(p.begin(), p.end());
      vector< Point > ch(2 * n);
      for(int i = 0; i < n; ch[k++] = p[i++]) {
        while(k >= 2 && cross(ch[k - 1] - ch[k - 2], p[i] - ch[k - 1]) < 0) --k;
      }
      for(int i = n - 2, t = k + 1; i >= 0; ch[k++] = p[i--]) {
        while(k >= t && cross(ch[k - 1] - ch[k - 2], p[i] - ch[k - 1]) < 0) --k;
      }
      ch.resize(k - 1);
      return ch;
    } else {
      return p;
    }
  }

  double Convex_Diameter(Polygon &p)
  {
    int n = p.size();
    int is = 0, js = 0;
    for(int i = 1; i < n; i++) {
      if(p[i].y > p[is].y) is = i;
      if(p[i].y < p[js].y) js = i;
    }
    double maxdis = (p[is] - p[js]).norm();

    int maxi, maxj, i, j;
    i = maxi = is;
    j = maxj = js;
    do {
      if(cross(next(p, i) - curr(p, i), next(p, j) - curr(p, j)) >= 0) {
        j = (j + 1) % n;
      } else {
        i = (i + 1) % n;
      }
      if((p[i] - p[j]).norm() > maxdis) {
        maxdis = (p[i] - p[j]).norm();
        maxi = i;
        maxj = j;
      }
    } while(i != is || j != js);
    return maxdis;
  }
};

using namespace Geometry;

int main()
{
  int N, W, H, R, VX, VY;
  Point ball[10];

  while(cin >> N, N) {
    cin >> W >> H >> R >> VX >> VY;

    Point vv = Point(VX, VY) / Point(VX, VY).abs();
    Point curr;
    cin >> curr;
    --N;
    for(int i = 0; i < N; i++) cin >> ball[i];

    Point p1(R, R), p2(W - R, R), p3(W - R, H - R), p4(R, H - R);
    Segment rect[4];
    rect[0] = Segment(p1, p4);
    rect[1] = Segment(p2, p3);
    rect[2] = Segment(p1, p2);
    rect[3] = Segment(p3, p4);
    Segment dd(curr, curr + vv * 10000);

    int ret = -1;
    double pos = 1e18;
    int pre = 5;

    while(true) {
      for(int i = 0; i < N; i++) {
        double dist = Distance(dd, ball[i]);
        if(dist <= 2 * R) {
          Point p = Projection(dd, ball[i]);
          double length = Distance(dd.a, p) - sqrt(4 * R * R - dist * dist);
          if(length < pos) {
            pos = length;
            ret = i + 2;
          }
        }
      }
      if(pos < 1e18) break;
      int nxt = 5;
      for(int i = 0; i < 4; i++) {
        if(pre == i) continue;
        if(Intersect(dd, rect[i])) {
          Line l(rect[i].a, rect[i].b);
          dd = Segment(Reflection(l, dd.a), Reflection(l, dd.b));
          nxt = i;
          break;
        }
      }
      if(nxt == 5) break;
      pre = nxt;
    }

    cout << ret << endl;
  }
}

Measured memory_bytes: 3060