#include<bits/stdc++.h>
using namespace std;
const long double pi=acosl(-1.0);
struct point{
    long double x,y,rd;
    void in(){scanf("%Lf %Lf",&x,&y);}
    void out(){printf("%Lf %Lf\n",x,y);}
    point(long double xx=0,long double yy=0){x=xx,y=yy;}
    point operator + (const point& a)const{return point(x+a.x,y+a.y);}
    point operator - (const point& a)const{return point(x-a.x,y-a.y);}
    long double operator *(const point& a)const{return x*a.x+y*a.y;}
    long double operator ^(const point& a)const{return x*a.y-y*a.x;}
    bool operator < (const point& a)const{return rd<a.rd;}
};
long double len(const point& a){return sqrtl(a*a);}
long double rad(const point& a){return atan2l(a.y,a.x);}
const int maxn=500013;
point p[maxn];
long double cal(long double t,long double l,long double r){
    long double w=(r-l);
    if(w<=0) w+=pi+pi;
    long double ans=0;
    while(t>=pi+pi)t-=pi+pi,ans+=w;
    if(l<r)return ans+max(0.0l,min(t,r)-l);
    return ans+max(t-l,0.0l)+min(t,r);
}
int main(){
    int n;point s;long double d,t;
    scanf("%d",&n);s.in();
    scanf("%Lf %Lf",&d,&t);
    for(int i=1;i<=n;i++) p[i].in();
    for(int i=1;i<=n;i++) p[i].rd=rad(p[i]);
    sort(p+1,p+1+n);
    long double l,r;
    if(p[n].rd-p[1].rd<pi){
        long double dl=asinl(d/len(p[1]));
        long double dr=asinl(d/len(p[n]));
        l=p[1].rd-dl;
        r=p[n].rd+dr;
    }
    else{
        int pos1=n;
        while(p[pos1].rd-p[pos1-1].rd<pi) pos1--;
        int pos2=pos1-1;
        long double dl=asinl(d/len(p[pos1])),dr=asinl(d/len(p[pos2]));
        l=p[pos1].rd-dl;
        r=p[pos2].rd+dr;
    }
    if(l>=2*pi) l-=2*pi;
    if(r>=2*pi) r-=2*pi;
    if(l<0) l+=2*pi;
    if(r<0) r+=2*pi;
    printf("%.15Lf\n",cal(rad(s)+t,l,r)-cal(rad(s),l,r));
}