#include <iostream>
#include <iomanip>
#include <complex>
#include <vector>
#include <algorithm>
#include <cmath>
#include <array>
using namespace std;
const double EPS = 1e-8;
const double INF = 1e12;
#define EQ(n,m) (abs((n)-(m)) < EPS)
#define X real()
#define Y imag()

typedef complex<double> P;
typedef vector<P> VP;
struct L : array<P, 2>{
    L(const P& a, const P& b){ at(0)=a; at(1)=b; }
    L(){}
};
struct C{
    P p;
    double r;
    C(const P& p, const double& r) : p(p), r(r) {}
    C(){}
};
namespace std{
    bool operator < (const P& a, const P& b){
        return (a.X!=b.X) ? a.X<b.X : a.Y<b.Y;
    }
    bool operator == (const P& a, const P& b){
        return abs(a-b) < EPS;
    }
}

double dot(P a, P b){
    return (conj(a)*b).X;
}
double cross(P a, P b){
    return (conj(a)*b).Y;
}
int ccw(P a, P b, P c){
    b -= a;
    c -= a;
    if(cross(b,c) > EPS) return +1; //ccw
    if(cross(b,c) < -EPS) return -1; //cw
    if(dot(b,c) < -EPS) return +2; //c-a-b
    if(abs(c)-abs(b) > EPS) return -2; //a-b-c
    return 0; //a-c-b
}
P unit(const P &p){
    return p/abs(p);
}

double distanceLP(const L &l, const P &p) {
    return abs(cross(l[1]-l[0], p-l[0])) /abs(l[1]-l[0]);
}
double distanceSP(const L &s, const P &p) {
    if(dot(s[1]-s[0], p-s[0]) < EPS) return abs(p-s[0]);
    if(dot(s[0]-s[1], p-s[1]) < EPS) return abs(p-s[1]);
    return distanceLP(s, p);
}
bool intersectSP(const L& s, const P &p){
    return abs(cross(s[0]-p, s[1]-p))<EPS  && dot(s[0]-p, s[1]-p)<EPS;
}
bool intersectSS(const L& a, const L& b){
    return ( ccw(a[0],a[1],b[0]) *ccw(a[0],a[1],b[1]) <= 0 ) &&
        ( ccw(b[0],b[1],a[0]) *ccw(b[0],b[1],a[1]) <= 0 );
}

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]);
}
P reflection(const L& l, const P& p) {
    return p + 2.0*(projection(l, p) -p);
}
bool isParallel(const P &a, const P &b){
    return abs(cross(a,b)) < EPS;
}
bool isParallel(const L &a, const L &b){
    return isParallel(a[1]-a[0], b[1]-b[0]);
}

P crosspointLL(const L &l, const L &m) {
  double A = cross(l[1]-l[0], m[1]-m[0]);
  double B = cross(l[1]-l[0], l[1]-m[0]);
  return m[0] + B/A *(m[1]-m[0]);
}

VP crosspointCL(const C &c, const L &l){
    VP ret;
    P mid = projection(l, c.p);
    double d = distanceLP(l, c.p);
    if(EQ(d, c.r)){
        ret.push_back(mid);
    }else if(d < c.r){
        double len = sqrt(c.r*c.r -d*d);
        ret.push_back(mid +len*unit(l[1]-l[0]));
        ret.push_back(mid -len*unit(l[1]-l[0]));
    }
    return ret;
}
VP crosspointCS(const C &c, const L &s){
    VP ret;
    VP cp = crosspointCL(c,s);
    for(int i=0; i<(int)cp.size(); i++){
        if(intersectSP(s, cp[i])){
            ret.push_back(cp[i]);
        }
    }
    return ret;
}

int main(){
    while(1){
        int n;
        cin >> n;
        if(n==0) break;

        double w,h,r,vx,vy;
        cin >> w >> h >> r >> vx >> vy;
        VP rec{P(r, r), P(w-r, r), P(w-r, h-r), P(r, h-r)};
        P dir = unit(P(vx, vy));

        VP p(n);
        for(int i=0; i<n; i++){
            double x,y;
            cin >> x >> y;
            p[i] = P(x, y);
        }
        
        P pos = p[0];
        double limit = 1e4;
        int ans = -1;
        while(limit > 0){
            P ep = pos +dir*1e4;
            L ray(pos, ep);
            bool touch = false;
            P cp(INF, INF);
            for(int i=1; i<n; i++){
                if(distanceSP(ray, p[i]) < 2*r +EPS){
                    VP cpcs = crosspointCS(C(p[i], 2*r), ray);
                    for(P p: cpcs){
                        if(abs(pos -p) < abs(pos -cp)){
                            cp = p;
                            ans = i+1;
                        }
                    }
                    touch = true;
                }
            }
            if(touch){
                limit -= abs(pos -cp);
                break;
            }

            bool corner = false;
            for(int i=0; i<4; i++){
                if(intersectSP(ray, rec[i])){
                    limit -= 2*abs(pos -rec[i]);
                    dir = -dir;
                    corner = true;
                    break;
                }
            }
            for(int i=0; i<4 && !corner; i++){
                L edge(rec[i], rec[(i+1)%4]);
                if(!isParallel(ray, edge) && intersectSS(ray, edge)){
                    P cpll = crosspointLL(ray, edge);
                    if(cpll == pos) continue;
                    P to = reflection(edge, ep);
                    limit -= abs(cpll -pos);
                    pos = cpll;
                    dir = unit(to -cpll);
                    break;
                }
            }
        }

        if(limit < -EPS || ans == -1){
            cout << -1 << endl;
        }else{
            cout << ans << endl;
        }
    }
    return 0;
}


Measured memory_bytes: 3192