#include <iostream>
#include <algorithm>
#include <cmath>
#include <iomanip>
const int N = 110;
const double eps = 1e-12;
const double pi = acos(-1.0);
double n, x, y, d, t;

struct Point{
    double x, y;
    Point() :x(0), y(0) {}
    Point(double xx, double yy) :x(xx), y(yy) {}
} p[N];
struct Line{
    Point s, e;
    Line() :s(Point()), e(Point()) {}
    Line(Point xx, Point yy) :s(xx), e(yy) {}
} a[N], q[N];
Point operator+(Point a, Point b){
    return Point(a.x+b.x, a.y+b.y);
}
Point operator-(Point a, Point b){
    return Point(a.x-b.x, a.y-b.y);
}
Point operator*(Point a, double t){
    return Point(a.x*t, a.y*t);
}
double operator*(Point a, Point b){ 
    return a.x*b.y - a.y*b.x;
}
double angle(Line& a){ 
    return std::atan2(a.e.y-a.s.y, a.e.x-a.s.x);
}

int main()
{
    std::cin >> n >> x >> y >> d >> t;
    Point o(0, 0);
    std::cin >> p[1].x >> p[1].y;
    Point maxpoint = p[1], minpoint = p[1];
    Line maxline(o, p[1]), minline(o, p[1]);
    //std::cout << angle(minline) << '\n';

    for(int i=2; i<=n; i++){
        std::cin >> p[i].x >> p[i].y;
        Line tmp(o, p[i]);
        //std::cout << angle(tmp) << '\n';
        if(angle(tmp) > angle(maxline)){
            maxpoint = p[i];
            maxline = tmp;
        }
        if(angle(tmp) < angle(minline)){
            minpoint = p[i];
            minline = tmp;
        }
    }
    
    double maxd = std::sqrt(maxpoint.x*maxpoint.x+maxpoint.y*maxpoint.y-d*d);
    double maxa = (std::asin(d/sqrt(maxpoint.x*maxpoint.x+maxpoint.y+maxpoint.y)) + angle(maxline));
    //std::cout << maxa << '\n';
    Point maxcut(maxd*std::cos(maxa), maxd*std::sin(maxa));
    if(std::fabs(maxcut.x) < eps) maxcut.x = 0; if(std::fabs(maxcut.y) < eps) maxcut.y = 0;
    //std::cout << maxcut.x << ' ' << maxcut.y << '\n';

    double mind = std::sqrt(minpoint.x*minpoint.x+minpoint.y*minpoint.y-d*d);
    double mina = (angle(minline) - std::asin(d/sqrt(minpoint.x*minpoint.x+minpoint.y*minpoint.y)));
    Point mincut(maxd*std::cos(mina), maxd*std::sin(mina));
    //std::cout << std::fixed << std::setprecision(12) << mincut.x << ' ' << std::max(eps, mincut.x) << '\n';
    if(std::fabs(mincut.x) < eps) mincut.x = 0; if(std::fabs(mincut.y) < eps) mincut.y = 0;
    //std::cout << mincut.x << ' ' << mincut.y << '\n';
    maxline = Line(o, maxcut); minline = Line(o, mincut);
    
    double ans = 0;
    int k=0;
    double a1 = angle(maxline), a2 = angle(minline);
    if(t > 2*pi){
        k = int(t/2/pi);
        
        if(a1 * a2 >= 0) ans += std::fabs(a1-a2)*k;
        else ans += (a1+a2)*k;
    }
    //std::cout << ans << '\n';
    
    if(maxcut.x >= 0 && mincut.y >= 0){
        if(mincut.x >= 0 && mincut.y >= 0){
            if(t >= a2){
                if(t > a1) ans += std::fabs(a1-a2);
                else ans += std::fabs(t-a2);
            }
        } else if(mincut.x >= 0 && mincut.y < 0){
            if(t > a1){
                if(t >= 2*pi+a2){
                    ans += a1 + std::fabs(t-2*pi-a2);
                } else ans += a1;
            } else ans += t;
        } else if(mincut.x < 0 && mincut.y >= 0){
            //no case
        } else{
            if(t > a1){
                if(t >= 2*pi+a2){
                    ans += a1 + std::fabs(t-2*pi-a2);
                } else ans += a1;
            } else ans += t;
        }
    } else if(maxcut.x >= 0 && mincut.y < 0){
        if(mincut.x >= 0 && mincut.y >= 0){
            // no case
        } else if(mincut.x >= 0 && mincut.y < 0){
            if(t > 2*pi+a2){
                if(t > 2*pi+a1) ans += std::fabs(a1-a2);
                else ans += std::fabs(t-2*pi-a2);
            }
        } else if(mincut.x < 0 && mincut.y >= 0){
            // no case
        } else{
            if(t > 2*pi+a2){
                if(t > 2*pi+a1) ans += std::fabs(a1-a2);
                else ans += std::fabs(t-2*pi-a2);
            }
        }
    } else if(maxcut.x < 0 && mincut.y >= 0){
        if(mincut.x >= 0 && mincut.y >= 0){
            if(t >= a2){
                if(t <= a1) ans += t-a2;
                else ans += a1-a2;
            }
        } else if(mincut.x >= 0 && mincut.y < 0){
            if(t > a1){
                if(t >= 2*pi+a2){
                    ans += a1 + (t-2*pi-a2);
                } else ans += a1;
            } else ans += t;
        } else if(mincut.x < 0 && mincut.y >= 0){
            if(t >= a2){
                if(t > a1) ans += a1-a2;
                else ans += t-a2;
            }
        } else{
            if(t > a1){
                if(t >= 2*pi+a2){
                    ans += a1 + (t-2*pi-a2);
                } else ans += a1;
            } else ans += t;
        }
    } else{
        if(mincut.x >= 0 && mincut.y >= 0){
            // no case
        } else if(mincut.x >= 0 && mincut.y < 0){
            // no case
        } else if(mincut.x < 0 && mincut.y >= 0){
            // no case
        } else{
            if(t > 2*pi+a2){
                if(t > 2*pi+a1) ans += std::fabs(a1-a2);
                else ans += std::fabs(t-2*pi-a2);
            }
        }
    }
    std::cout << std::fixed << std::setprecision(12) << ans;

    //std::cout << angle(maxline)/pi << '\n';
    //std::cout << maxpoint.x << ' ' << maxpoint.y << '\n';
    //std::cout << minpoint.x << ' ' << minpoint.y << '\n';

    return 0;
}