#include<iostream>
#include <bits/stdc++.h>

#define ll long long
#define ld long double
#define IO ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
using namespace std;
const int N = 3e5 + 5, inf = 2e9;

void doWork() {
    int n, l, v;
    cin >> n >> l >> v;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    cout << fixed << setprecision(9);
    if (n == 1) {
        if (a[0] >= v) {
            cout << (ld) l / a[0];
        } else {
            cout << (ld) 2 * l / (a[0] + v);
        }
        return;
    }

    sort(a.begin(), a.end());
    ld sum1 = 0, sum2 = 0;
    for (auto i: a) {
        sum1 += (ld) 1 / (i + v);
        sum2 += (ld) i / (i + v);
    }

    ld ans = 1e9;
    ld t = 0;
    ans = min(ans, t + 2 * (sum1 * l - t * sum2) / n);

    while (!a.empty()) {
        t = (ld) l / a.back();
        sum2 -= (ld) a.back() / (a.back() + v);
        sum1 -= (ld) 1 / (a.back() + v);
        a.pop_back();

        ans = min(ans, t + 2 * (sum1 * l - t * sum2) / n);
    }
    cout << ans;
}


int main() {
    IO
    int t = 1;
    //   cin >> t;
    for (int i = 1; i <= t; i++) {
        //  cout << "Case #" << i << ": ";
        doWork();
    }
}