#include<bits/stdc++.h>
using namespace std;
typedef long double ld;
const ld pi=acos(-1.0l);
struct point{
    ld x,y,rd;
    void in(){scanf("%Lf %Lf",&x,&y);}
    point operator + (const point& a)const{return {x+a.x,y+a.y};}
    point operator - (const point& a)const{return {x-a.x,y-a.y};}
    ld operator *(const point& a)const{return x*a.x+y*a.y;}
    ld operator ^(const point& a)const{return x*a.y-y*a.x;}
    bool operator < (const point& a)const{return rd<a.rd;}
};
ld len(const point& a){return sqrtl(a*a);}
ld rad(const point& a){return atan2l(a.y,a.x);}
const int maxn=105;
point p[maxn];
ld cal(ld t,ld l,ld r){
    ld w=r-l;
    if(w<0) w+=2*pi;
    ld ans=0;
    while(t>pi+pi)t-=pi+pi,ans+=w;
    if(l<r){
        return ans+max(0.0l,min(t,r)-l);
    }
    else{
        return ans+max(t-l,0.0l)+min(t,r);
    }
}
typedef ld ld;
int main(){
    int n;
    point s;
    ld d,t;
    scanf("%d",&n);s.in();scanf("%Lf %Lf",&d,&t);
    for(int i=1;i<=n;i++) p[i].in(),p[i].rd=rad(p[i]);
    ld v=rad(s);
    sort(p+1,p+1+n);
    ld l=pi+pi,r=0;
    while(p[n].rd-p[1].rd+(1e-9)>=pi){
        ld dd=pi+pi-p[n].rd;
        for(int i=1;i<=n;i++)p[i].rd+=dd;
        v+=dd;
        for(int i=1;i<=n;i++)if(p[i].rd+(1e-9)>pi+pi)p[i].rd=0;
        sort(p+1,p+1+n);
    }
    for(int i=1;i<=n;i++)l=min(l,p[i].rd),r=max(r,p[i].rd);
    for(int i=1;i<=n;i++){
        ld di=asin(d/len(p[i]));
        l=min(l,p[i].rd-di),r=max(r,p[i].rd+di);
    }
    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(v+t,l,r)-cal(v,l,r));
}