#include <bits/stdc++.h>
using namespace std;
#define debug(x) cerr << #x << " = " << x << endl

#define endl '\n'
#define fori(x, y) for (int i=(x);i<=(y);++i)
#define forj(x, y) for (int j=(x);j<=(y);++j)
#define fork(x, y) for (int k=(x);k<=(y);++k)

#define double long double
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<double,double> pdd;

const double PI = acos(-1.0);

/*
3 1 0 1 10
-1 -2
-2 -1
-2 -2
*/
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    ll n, x0, y0, d;
    double t;
    cin >> n >> x0 >> y0 >> d >> t;
    vector<pll> vec;
    fori(1, n) {
        int x, y;
        cin >> x >> y;
        vec.push_back({x, y});
    }
    
    bool in = false;
    for (auto [x, y]: vec) {
        if (x*x+y*y<=d*d) {
            in = true;
            break;
        }
    }
    cout << fixed << setprecision(15);
    if (in) {
        cout << t << endl;
        return 0;
    }

    vector<pdd> rang;
    for (auto [x, y]: vec) {
        double s = 0;
        if (x == 0&&y > 0) s = PI/2;
        else if (x == 0&&y < 0) s = -PI/2;
        else {
            s = atan((double)y/x);
            if (x<0) s = s+PI;
        }
        double r = acos((double)d/sqrt(x*x+y*y));
        rang.push_back({s, r});
        // debug(s);
        // debug(r);
    }
    // exist ????
    int cnt1 = 0, cnt2 = 0;
    for (auto [x, y]: vec) {
        if (y<0&&x<0) cnt1++;
        if (y<0&&x>0) cnt2++;
    }
    if (cnt1&&cnt2) for (auto& [s, r]: rang) if (s<PI/2) s += 2*PI;

    double le = 1e9, ri = -1e9;
    for (auto [s, r]: rang) {
        // debug(s);
        // debug(r);
        le = min(le, s-PI/2+r);
        ri = max(ri, s+PI/2-r);
    }
    // debug(le);
    // debug(ri);

    int per = t/(2*PI);
    double ans = 0;
    ans += per*(ri-le);
    // debug(ans);

    t -= per*2*PI;
    double ang = 0;
    if (x0 == 0&&y0 > 0) ang = PI/2;
    else if (x0 == 0&&y0 < 0) ang = -PI/2;
    else {
        ang = atan((double)y0/x0);
        if (x0<0) ang = ang+PI;
    }
    // debug(ang);

    if (ang > ri) ang -= 2*PI;
    if (ang>=le&&ang<=ri) {
        double dis = ri-ang;
        // debug(dis);
        if (t<dis) {
            ans += t;
            cout << ans << endl;
            return 0;
        }
        ans += dis;
        t -= dis;
        dis = le-ri+2*PI;
        if (t<dis) {
            cout << ans << endl;
            return 0;
        }
        t -= dis;
        ans += t;
        cout << ans << endl;
        return 0;
    }

    double dis = le-ang;
    if (t<dis) {
        cout << ans << endl;
        return 0;
    }
    t -= dis;
    dis = ri-le;
    ans += min(dis, (double)t);
    cout << ans << endl;
    return 0;
}