#include <bits/stdc++.h>

#define x first
#define y second

using namespace std;

typedef double db;
typedef pair<int, int> PII;

const int N = 110;
const db PI = acos(-1);

int n, sx, sy, d, t, order[N], cnt;
PII cv[N];
db rads[N], alpha[N], rr[2], res, ans, true_ans = 0;

void rotate90(int &x, int &y) {
	int t = y;
	y = x, x = -t;
}
db rad(int x, int y) {
	return atan2(y, x);
}
bool check() {
	for(int i = 1; i <= n; i ++) {
		if(cv[i].x <= 0 && cv[i].y <= 0) return false;
	}
	bool ok = false;
	for(int i = 1; i <= n; i ++) {
		if(cv[i].x > 0 && cv[i].y > 0) return false;
	}
	return ok;
}
db dist(int x, int y) {
	return sqrt(x*x + y*y);
}
db shift(db r) {
	db ret = r + 3./4 * PI;
	ret = ret - int(ret/2/PI)*2*PI;
	while(ret >= 2*PI) ret -= 2*PI;
	while(ret < 0) ret += 2*PI;
	return ret;
}
void work() {
	rads[0] = rad(sx, sy);
	iota(order+1, order+n+1, 1);
	for(int i = 1; i <= n; i ++) rads[i] = rad(cv[i].x, cv[i].y);
	for(int i = 1; i <= n; i ++) alpha[i] = asin(1.*d/dist(cv[i].x, cv[i].y));
	sort(order+1, order+n+1, [](auto x, auto y) {
		return shift(rads[x]-alpha[x]) < shift(rads[y]-alpha[y]);
	});
	rr[0] = shift(rads[order[1]] - alpha[order[1]]);
	sort(order+1, order+n+1, [](auto x, auto y) {
		return shift(rads[x]+alpha[x]) < shift(rads[y]+alpha[y]);
	});
	rr[1] = shift(rads[order[n]] + alpha[order[n]]);
	ans = 1.*cnt * (rr[1]-rr[0]);
	// cerr << ans << '\n';
	rads[0] = shift(rads[0]);
	// cerr << rr[0]/PI << ' ' << rr[1]/PI << ' ' << rads[0]/PI << ' ' << res/PI << '\n';
	if(rads[0] >= rr[0] && rads[0] <= rr[1]) {
		ans += min(rr[1]-rads[0], res);
		res -= rr[1]-rads[0];
		if(res >= 2*PI-rads[0] + rr[0]) {
			res -= 2*PI-rads[0] + rr[0];
			ans += min(rr[1]-rr[0], res);
		}
	}
	else {
		if(rads[0] > rr[1] && res >= 2*PI-rads[0] + rr[0]) {
			res -= 2*PI-rads[0] + rr[0];
			ans += min(rr[1]-rr[0], res);
		}
		if(rads[0] < rr[0] && res >= rr[0]-rads[0]) {
			res -= rr[0]-rads[0];
			// cerr << res << ' ' << rr[1]-rr[0] << '\n';
			ans += min(rr[1]-rr[0], res);
		}
	}
	// cout << ans << '\n';
}
int main() {
	ios::sync_with_stdio(0); cin.tie(0);
	cout << fixed << setprecision(12);
	cin >> n >> sx >> sy >> d >> t;
	for(int i = 1; i <= n; i ++) cin >> cv[i].x >> cv[i].y;
	true_ans = 0;
	for(int u = 0; u < 4; u ++) {
		// if(check()) break;
		cnt = 1.*t/2/PI;
		res = t - 1.*cnt*2*PI;
		work();
		true_ans = max(true_ans, ans);
		rotate90(sx, sy);
		for(int i = 1; i <= n; i ++) rotate90(cv[i].x, cv[i].y);
	}
	cout << true_ans << '\n';
	return 0;
}