#include<iostream>
using namespace std;
#include<vector>
#include<cmath>
#include<iomanip>

double slen(double x, double y) {
	return x * x + y * y;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	double pi = acos(-1);

	int n = 0, x = 0, y = 0, d = 0, t = 0;
	cin >> n >> x >> y >> d >> t;

	double beg = atan2(y, x);

	vector<pair<int, int>> point(n);
	for (int i = 0; i < n; ++i) cin >> point[i].first >> point[i].second;

	bool ok1 = false, ok2 = false;
	for (int i = 0; i < n; ++i) {
		if (point[i].first < 0 && point[i].second >= 0) ok1 = true;
		if (point[i].first < 0 && point[i].second < 0) ok2 = true;
	}

	double ans = 0;

	if (ok1 && ok2) {
		double mn = atan2(point[0].second, point[0].first);
		if (mn < 0) mn += 2 * pi;
		double mx = mn;
		for (int i = 0; i < n; ++i) {
			double f = atan2(point[i].second, point[i].first);
			if (f < 0) f += 2 * pi;
			double l = slen(point[i].first, point[i].second);
			l = atan2(d, sqrt(l - d * d));
			mx = max(mx, f + l);
			mn = min(mn, f - l);
		}
		if (beg < 0) beg += 2 * pi;
		int circle = t / (2 * pi);
		ans += circle * (mx - mn);
		double a = t - circle * 2 * pi;
		if (mn >= beg) {
			if (beg + a < mx) ans += beg + a - mn;
			else ans += mx - mn;
		}
		else {
			if (beg + a < mx) ans += a;
			else ans += mx - beg;
		}
	}
	else {
		double mn = atan2(point[0].second, point[0].first);
		double mx = mn;
		for (int i = 0; i < n; ++i) {
			double f = atan2(point[i].second, point[i].first);
			double l = slen(point[i].first, point[i].second);
			l = atan2(d, sqrt(l - d * d));
			mx = max(mx, f + l);
			mn = min(mn, f - l);
		}
		int circle = t / (2 * pi);
		ans += circle * (mx - mn);
		double a = t - circle * 2 * pi;
		if (mn >= beg) {
			if (beg + a < mx) ans += beg + a - mn;
			else ans += mx - mn;
		}
		else {
			if (beg + a < mx) ans += a;
			else ans += mx - beg;
		}
	}

	cout << fixed << setprecision(15) << ans << "\n";
	return 0;
}