#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define double long double

const double eps=1e-8;
int sgn(double x){
    if(x>eps)return 1;
    if(x<-eps)return -1;
    return 0;
} 

struct vec{
    double x,y;
    vec operator-(vec a){return {x-a.x,y-a.y};}
    vec operator-(){return {-x,-y};}
    double len(){return hypotl(x,y);}
    vec rot90(){return {-y,x};}
    vec rotate(double c){
        return {x*cosl(c)-y*sinl(c),x*sinl(c)+y*cosl(c)};
    }
};

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

struct cir{
    vec o{0,0};
    double r;
};

int getTangents(vec p,cir c,vec& v0,vec& v1){
    vec u=c.o-p;
    double dist=u.len();
    if(sgn(dist-c.r)<0)return 0;
    if(!sgn(dist-c.r)){
        v0=u.rot90();
        return 1;
    }
    double ang=asinl(c.r/dist);
    v0=u.rotate(-ang);
    v1=u.rotate(ang);
    return 2;
}

const double pi=acosl(-1);

void solve(){
    int n;
    vec d;
    cir c;c.o={0,0};
    double t;
    cin>>n>>d.x>>d.y>>c.r>>t;

    vector<vec> v(n);
    for(int i=0;i<n;i++){
        cin>>v[i].x>>v[i].y;
    }
    vec l0,r0;
    for(int i=0;i<n;i++){
        vec l,r;
        getTangents(v[i],c,l,r);
        l=-l;r=-r;
        if(i==0)l0=l,r0=r;
        else{
            if(sgn(cross(l,l0))>=0)l0=l;
            if(sgn(cross(r0,r))>=0)r0=r;
        }
        // cout<<atan2(l.y,l.x)<<" "<<atan2(r.y,r.x)<<"\n";
    }
    double a=atan2l(d.y,d.x);

    double al=atan2l(l0.y,l0.x);
    double ar=atan2l(r0.y,r0.x);
    al-=a;ar-=a;
    if(sgn(al)<0)al+=2*pi;
    if(sgn(ar)<0)ar+=2*pi;
    a=ar-al;if(sgn(a)<0)a+=2*pi;

    double cnt=floorl(t/(2*pi));
    double ans=cnt*a;
    t-=cnt*(2*pi);
    if(ar>=al){
        if(t>al);
        ans+=min(t-al,ar-al);
    }
    else{
        ans+=min(t,ar);
        if(t>al)ans+=t-al;
    }

    
    // cout<<atan2(l0.y,l0.x)<<" "<<atan2(r0.y,r0.x)<<"\n";
    cout<<fixed<<setprecision(12)<<ans<<"\n";

}

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n=1;
    //cin>>n;
    while(n--)solve();
    return 0;
}