#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define double long double

const double pi = acos(-1);
#define x0 laksjdfla
#define y0 laksjdf
int n, x0, y0, d;
double t;
int x[111], y[111];
double in[111], out[111];
double norm(double t) {
    while (t < -pi) t += pi*2;
    while (t >= pi) t -= pi*2;
    return t;
}
void solve() {
    cin >> n >> x0 >> y0 >> d >> t;
    for (int i = 1; i <= n; i++) {
        cin >> x[i] >> y[i];
        double t = asin(1. * d / sqrt(x[i] * x[i] + y[i] * y[i]));
        in[i] = atan2(y[i], x[i]) - t;
        out[i] = atan2(y[i], x[i]) + t;
    }
    int u = 1, v = 1;
    for (int i = 1; i <= n; i++) {
        if (norm(in[u] - in[i]) > 0) u = i;
        if (norm(out[i] - out[v]) > 0) v = i;
    }
    double l = norm(in[u]);
    double r = norm(out[v]);
    vector<pair<double, double>> o, p;
    auto add = [&](vector<pair<double, double>>& o, double l, double r) {
        if (l <= r) {
            o.push_back(make_pair(l, r));
        } else {
            o.push_back(make_pair(l, pi));
            o.push_back(make_pair(-pi, r));
        }
    };
    // cerr<<l<<" "<<r<<"\n";

    add(o, l, r);

    double ans = 0;
    double s = 0;
    for (auto oo : o) s += oo.second - oo.first;
    int round = t / (pi*2);
    ans += round * s;
    t -= round * (pi*2);
    // cout<<t<<" "<<round<<"\n";
    double L = norm(atan2(y0, x0));
    double R = norm(L + t);
    // cerr<<L<<" "<<R<<"\n";
    add(p, L, R);

    for (auto oo : o) {
        for (auto pp : p) {
            // cerr<<oo.first<<" "<<oo.second<<" "<<pp.first<<" "<<pp.second<<"\n";
            ans += max((double)0., min(oo.second, pp.second) - max(oo.first, pp.first));
        }
    }
    cout <<fixed<<setprecision(20)<< ans << "\n";
    
}
signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    int t = 1;
    // cin >> t;
    while (t--) solve();
    return 0;
}