#include <bits/stdc++.h>

using namespace std;

const int MAX_N = 200000 + 5;
const double EPS = 1e-3;

int N, M, L, V, v[MAX_N];
double t1[MAX_N], t2[MAX_N], suf[MAX_N];
pair <double, int> event[MAX_N << 1];

double solve(int n, double t) {
    double cur = 0; M = 0;
    static double t1[MAX_N], t2[MAX_N];
    for (int i = n; i > 0; i --) {
        t1[i] = (L - v[i] * t) / (double)v[i];
        t2[i] = 2.0 * (L - v[i] * t) / (v[i] + V);
        cur += t1[i];
        event[++ M] = pair((L - v[i] * t) / (v[i] + V), i);
        if (v[i] > V) event[++ M] = pair(0.5 * (L - v[i] * t) / v[i], -i);
    }
    sort(event + 1, event + M + 1);
    double ans = cur;
    int cnt = 0;
    for (int i = 1; i <= M; i ++) {
        auto [t0, pos] = event[i];
        if (pos < 0) {
            cnt ++;
            cur -= t1[-pos];
        }else {
            if (v[pos] > V) {
                cnt --;
            }else {
                cur -= t1[pos];
            }
            cur += t2[pos];
        }
        ans = min(ans, cur + 2.0 * cnt * t0);
    }
    return ans + t * n;
}

int main() {
    scanf("%d%d%d", &N, &L, &V);
    for (int i = 1; i <= N; i ++) {
        scanf("%d", v + i);
        t1[i] = (double)L / v[i];
        t2[i] = 2.0 * L / (v[i] + V);
    }
    for (int i = N; i > 0; i --) suf[i] = suf[i + 1] + t1[i];
    int l = 1, r = N - 1;
    double ans = solve(N, 0);
	while (l < r) {
		int mid = l + r >> 1;
		double slope = solve(mid + 1, t1[mid + 2]) + suf[mid + 2] - solve(mid, t1[mid + 1]) - suf[mid + 1];
		if (slope < -EPS) l = mid + 1;
		else r = mid;
	}
    for (int i = max(1, r - 5); i <= min(N - 1, r + 5); i ++) ans = min(ans, solve(i, t1[i + 1]) + suf[i + 1]);
    printf("%.10lf\n", ans / N);
    return 0;
}