#include <bits/stdc++.h>
using namespace std;
#define int long long
// #define endl '\n'

constexpr int maxn = 2e5 + 5;
constexpr double pi = acos(-1);

double f(double x, double y)
{
    double res = 0;
    if (x == 0)
    {
        if (y > 0) res = pi / 2;
        else res = pi * 3 / 2;
    }
    else
    {
        res = atan(y / x);
        // cout << x << " " << y << " " << y / x << " " << res << endl;
        if (y < 0 || (y == 0 && x < 0)) res += pi / 2;
    }
    return res;
}

void solve()
{
    int n, x0, y0, d, t;
    cin >> n >> x0 >> y0 >> d >> t;
    vector<int> x(n + 1, 0), y(n + 1, 0);
    for (int i = 1; i <= n; i++) cin >> x[i] >> y[i];
    double avex = 0, avey = 0;
    for (int i = 1; i <= n; i++) avex += x[i], avey += y[i];
    avex /= n; avey /= n;
    double st = f(avex, avey);
    st += pi;
    if (st >= 2 * pi) st -= 2 * pi;
    if (st != 0) st = st - 2 * pi;
    vector<double> mx(n + 1, 0), mn(n + 1, 0);
    for (int i = 1; i <= n; i++)
    {
        double dir = f(x[i], y[i]) - st;
        if (dir >= 2 * pi) dir -= 2 * pi;
        double seita = asin(d / sqrt(x[i] * x[i] + y[i] * y[i]));
        mx[i] = dir + seita;
        mn[i] = dir - seita;
    }
    double smx = mx[1], smn = mn[1];
    for (int i = 2; i <= n; i++) smx = max(smx, mx[i]), smn = min(smn, mn[i]);
    double dir = f(x0, y0) - st;
    if (dir >= 2 * pi) dir -= 2 * pi;
    int T = t / (2 * pi);
    t -= T * 2 * pi;

    double ans = T * (smx - smn);
    double l, r;
    if (dir + t >= 2 * pi)
    {
        l = max(dir, smn);
        r = min(2 * pi, smx);
        ans += max(0.0, r - l);
        l = smn;
        r = min(smx, dir + t - 2 * pi);
        ans += max(0.0, r - l);
    }
    else
    {
        r = min(dir + t, smx);
        l = max(dir, smn);
        ans += max(0.0, r - l);
    }

    printf("%.12lf", ans);
}

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