#include<bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
const double eps = 1e-7;
int s, t;
int n;
double a[N], sum[N];

bool check(double x)
{
    for(int i = 1;i <= n;i++)
    {
        sum[i] = sum[i - 1] + a[i] - x;
    }

    deque<int>q;
    for(int i = s;i <= n;i++)
    {
        while(q.size() && sum[i - s] < sum[q.back()])q.pop_back();
        q.push_back(i - s);//sum[r] - sum[l - 1];
        while(q.size() && i - q.front() > t)q.pop_front();
        if(q.size() && sum[i] - sum[q.front()] > 0)return true;
    }
    return false;   
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin >> n;
    cin >> s >> t;
    for(int i = 1;i <= n;i++)cin >> a[i];

    double l = -10000, r = 10000;
    while(r - l > eps)
    {
        double mid = (l + r) / 2.0;
        if(check(mid))l = mid;
        else r = mid;
//      cout << l << endl; 
    }
    printf("%.3f", l);
    return 0;
}